Sensors incorporated into tire plies to detect reversible deformation and/or temperature changes

ABSTRACT

Tires formed of one or more tire plies are disclosed. In some implementations, tire plies may include a temperature sensor that may detect a temperature of a respective tire ply. The temperature sensor may include one or more split-ring resonators (SRRs), each having a resonance frequency that changes in response to one or more of a change in an elastomeric property or a change in the temperature of a respective one or more tire plies. In some aspects, the temperature sensor may include an electrically-conductive layer dielectrically separated from a respective one or more SRRs.

CROSS-REFERENCE TO RELATED APPLICATIONS

This Patent Application is a continuation application claiming priorityto U.S. patent application Ser. No. 17/340,514 entitled “SENSORSINCORPORATED INTO TIRE PLIES TO DETECT REVERSIBLE DEFORMATION AND/ORTEMPERATURE CHANGES” and filed on Jun. 7, 2021, which is acontinuation-in-part of and claims priority to U.S. patent applicationSer. No. 16/829,355 entitled “TIRES CONTAINING RESONATING CARBON-BASEDMICROSTRUCTURES” and filed on Mar. 25, 2020 (now issued as U.S. Pat. No.11,446,966), which claims priority to U.S. Provisional PatentApplication No. 62/824,440 entitled “TUNING RESONANT MATERIALS FORVEHICLE SENSING” and filed on Mar. 27, 2019, to U.S. Provisional PatentApplication No. 63/036,118 entitled “CARBON-CONTAINING STICTION SENSORS”and filed on Jun. 8, 2020, to U.S. Provisional Patent Application No.63/094,223 entitled “SENSORS FOR ELASTOMER PROPERTY CHANGE DETECTION”and filed on Oct. 20, 2020, to U.S. Provisional Patent Application No.62/979,215 entitled “WASTE ENERGY HARVESTING AND POWERING IN VEHICLES”and filed on Feb. 20, 2020, and to U.S. Provisional Patent ApplicationNo. 62/985,550 entitled “RESONANT SERIAL NUMBER IN VEHICLE TIRES” andfiled on Mar. 5, 2020, all of which are assigned to the assignee hereof.The disclosures of all prior Applications are considered part of and areincorporated by reference in this Patent Application.

TECHNICAL FIELD

This disclosure generally relates to sensors and, more specifically, tosplit ring resonators that can detect various properties of tires of avehicle.

DESCRIPTION OF RELATED ART

Advances in vehicle power types, including hybrid and electric-onlysystems, have created an opportunity for further technologicalintegration. This is true especially as modern vehicles transition intofully autonomous driving and navigation, where technology (as opposed totrained and capable humans) must routinely monitor vehicle componentperformance and reliability to ensure continued vehicle occupant safetyand comfort. Traditional systems, such as tire pressure monitoringsystems (TPMSs), may fail to provide the high degree of fidelityrequired for high-performance (such as racing) or fully autonomousdriving applications. Such applications can present unique challenges,such as rapid vehicle component (such as tire) wear encountered indemanding driving or racing or failing to have a human driver presentcapable of checking tire performance during vehicle operation.

SUMMARY

This Summary is provided to introduce in a simplified form a selectionof concepts that are further described below in the DetailedDescription. This Summary is not intended to identify key features oressential features of the claimed subject matter, nor is it intended tolimit the scope of the claimed subject matter. Moreover, the systems,methods, and devices of this disclosure each have several innovativeaspects, no single one of which is solely responsible for the desirableattributes disclosed herein.

One innovative aspect of the subject matter described in this disclosuremay be implemented as a tire including a temperature sensor. In oneimplementation, the tire may include a tire body formed of one or moretire plies. One or more of the tire plies may include a temperaturesensor that can detect the temperature of a respective tire ply. In someaspects, the temperature sensor may include a ceramic material organizedas a matrix. In other aspects, the temperature sensor may include one ormore split-ring resonators (SRRs). Each SRR may have a natural resonancefrequency that may proportionately shift in response to one or more of achange in an elastomeric property of a respective one or more tire pliesor a change in the temperature. For example, the elastomeric propertymay include one or more of a reversible deformation, stress, or strain.An electrically-conductive metal-containing layer may be in contact witheach SRR.

In one implementation, the SRRs may include a first split-ring resonator(SRR) with first carbon particles. In some aspects, the first carbonparticles may uniquely resonate in response to an electromagnetic ping.The unique resonation may be based at least in part on a concentrationlevel of the first carbon particles within the first SRR. In someimplementations, the SRRs may include a second SRR adjacent to the firstSRR, where the second SRR includes second carbon particles that mayuniquely resonate in response to the electromagnetic ping. The uniqueresonation may be based at least in part on a concentration level of thesecond carbon particles within the second SRR.

In some implementations, the first carbon particles may include firstaggregates forming a first porous structure. The second carbon particlesmay include second aggregates forming a second porous structure, wherethe first and second porous structures may have mesoscale structuring.In one implementation, the first SRR and the second SRR may bethree-dimensionally (3D) printed onto a surface of the tire ply. Thefirst SRR may resonate at a first frequency in response to theelectromagnetic ping, and the second SRR may resonate at a secondfrequency in response to the electromagnetic ping, where the firstfrequency may be different than the second frequency. In some aspects,each of the first frequency and the second frequency may be associatedwith an encoded serial number.

In some implementations, an amplitude of resonance of the first SRR orthe second SRR may be indicative of an extent of wear of the tire ply.For example, an extent of shift of the natural resonance frequency inresponse to the electromagnetic ping of the first SRR and the second SRRmay be indicative of an amount of deformation of the tire ply. In oneimplementation, each of the first SRR and the second SRR may have anattenuation point, which may be associated with a frequency response tothe electromagnetic ping.

In one implementation, each of the first carbon particles and secondcarbon particles may be chemically bonded with the tire ply. In someaspects, each of the first SRR and the second SRR may have a principaldimension associated with one or more of an S-parameter or a frequencyof the electromagnetic ping. At least one of the first SRR or the secondSRR may have one of an oval shape, an elliptical shape, a rectangularshape, a square shape, a circle shape, or a curved line. In someaspects, one or more of the first SRR or the second SRR include acylindrical SRR.

In one implementation, the first SRR may be positioned outside thesecond SRR and the first SRR and the second SRR may be disposed withinan inner liner of the tire. In some aspects, the tire may have a treadedside, such that the SRRs disposed within a vicinity of the treaded side.In some aspects, each of the first SRR and the second SRR may have anegative effective permeability. In one implementation, each of thefirst SRR and the second SRR includes one or more ofelectrically-conducting materials, metals, electrically-conductingnon-metals, dielectric materials, or semiconducting materials. In someaspects, the first SRR and the second SRR may be positioned or arrangedas a pair of concentric rings.

Details of one or more implementations of the subject matter describedin this disclosure are set forth in the accompanying drawings and thedescription below. Other features, aspects, and advantages will becomeapparent from the description, the drawings, and the claims. Note thatthe relative dimensions of the following figures may not be drawn toscale.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 presents an in-situ vehicle control system, according to someimplementations.

FIG. 2 depicts a signal processing system, according to someimplementations.

FIG. 3 illustrates a signature classification system, according to someimplementations.

FIG. 4 depicts a series of tire condition parameters that can be sensed,according to some implementations.

FIG. 5 depicts a schematic diagram of an apparatus used for tuningmultiple plies of a tire, according to some implementations.

FIGS. 6 and 7 depict sets of example condition signatures that may beemitted from new tires formed of layers of carbon-containing tuned RFresonance materials, according to some implementations.

FIG. 8 depicts a top-down schematic view of an example split-ringresonator (SRR) configuration including two concentric SRRs, accordingto some implementations.

FIG. 9 depicts a schematic diagram showing a complete tire diagnosticssystem and apparatus, according to some implementations.

FIGS. 10 and 11 depict schematic diagrams indicating tire informationtransferred via telemetry into a navigation system, according to someimplementations.

FIG. 12 depicts resonant serial number-based digital encoding of vehicletires, according to some implementations.

FIG. 13 illustrates resonance mechanisms that contribute to the ensemblephenomenon arising from different proximally-present resonator types,according to some implementations.

FIG. 14 is an example temperature sensor, according to someimplementations.

FIG. 15 is a graph of measured resonant signature signal intensity oftire tread layer loss, according to some implementations.

FIG. 16 is a graph of measured resonant signature signal intensityrelative to the natural resonance frequency of SRRs, according to someimplementations.

FIG. 17 is a graph of signal intensity relative to chirp signalfrequency for SRRs that may resonate corresponding to an encoded serialnumber, according to some implementations.

FIG. 18A through FIG. 18Y depict carbonaceous materials used as aformative material, according to some implementations.

Like reference numbers and designations in the various drawings indicatelike elements.

DETAILED DESCRIPTION

Various implementations of the subject matter disclosed herein relategenerally to deploying durable sensors (e.g., split-ring resonators,SRRs), made from carbonaceous microstructures. The sensors may beincorporated within vehicle components, e.g., within the plies of thebody of a conventional, currently commercially available pneumatic(referring to air, nitrogen or other gas-filled) tire, next-generationairless solid tires, as well as in other positions, e.g., within vehiclebodywork. The sensors may be embedded within portions of tire pliesand/or tire tread, e.g., rubber in contact with pavement or ground.Routine tire usage results in degradation of contact surfaces,eventually resulting in bald (treadles) tires incapable of adequatelyadhering to road surfaces, especially in inclement weather conditions,e.g., snow, heavy rain, etc. Deterioration of tire plies containingsensors produces corresponding detectable changes in sensor responsebehavior, e.g., relative to both forward rotation and tire strainencountered in lateral tire sliding, e.g., “drifting,” a common maneuverin some enthusiast communities. In this way, both routine (e.g.,forward-rotation) tire deterioration can be detected by changes inexpected sensor resonance response behavior and loss of tire stiction(e.g., during drift maneuvers) by observing shifts in expected sensorresonance response behavior (e.g., as accomplished through frequencyshift-keying, a concept explained further below). Stiction, as commonlyunderstood, may imply the static friction that needs to be overcome toenable relative motion of stationary objects in contact, e.g., as may beencountered during performance driving maneuvers involving lateralmovement, such as drifting. This is comparison to kinetic and/or dynamicfriction, which may imply concurrent movement between both contactingsurfaces, etc.

The carbonaceous materials can be tuned during synthesis to achievespecific expected radio frequency (RF) signal shift (referring tofrequency shift) and signal attenuation (referring to the diminishmentof signal magnitude) behavior relative to RF signals emitted. Equipmentcapable of emitting the RF signals may include, for example, atransceiver mounted within one or wheel wells of a vehicle equipped withthe disclosed systems and/or by an inductor-capacitor (LC) circuit, alsoreferred to (interchangeably) as a tank circuit, LC circuit orresonator. The presently disclosed implementations do not require movingparts and are thereby less susceptible to wear and tear resultant ofroutine road usage. SRRs function with pre-existing vehicle electroniccomponents. Target RF resonance frequency values of disclosed ingredientcarbonaceous materials may be tuned within a reaction chamber or areactor to demonstrate interaction to yield target performancecharacteristics. The characteristics may be for any number ofapplications, e.g., knobby, low-pressure off-road tires as well asrace-track only slicks without tread. SRRs formed of unique carbonaceousmaterials demonstrate frequency shifting and/or signal attenuation atspecified radio frequencies (RF), e.g., 0.01 GHz to 100 GHz, which maybe tuned pursuant to desired applications. Regarding tunability, thecarbonaceous materials may be innately grown (e.g., self-nucleated) in areactor from a carbon-containing gaseous species without requiring aseed particle to generate ornate 3D structures.

Changes in the environment (e.g., snow, rain, etc.) surrounding avehicle equipped with the disclosed materials and systems may affect theresonance, frequency shifting, and/or signal attenuation behavior of theSRRs. As a result, even minute tire condition changes can be detectedand communicated to the driver. For example, should a tire plycontaining one or more SRRs contact a road surface (e.g.,forward-rotation) and thereby deteriorate over time, resonance of thatSRR within the deteriorating tire ply may change. Further, otherdetectable changes may occur during drifting (e.g., sideways movement)scenarios, such that signal response of the affected tire ply and/ortread layer containing the SRR may indicate the presence or absence ofthat tread layer, as well as the degree of wear. As a result, SRRs mayaccurately and precisely detect both abrupt or gradual transitions inweather or other environmental conditions (e.g., performance drivingmaneuvers).

Detectable changes and/or shifts in in RF range resonant frequencyresponse of SRRs may detected by stimulating the RF resonant materialswithin each SRR with an electromagnetic (EM) signal having a knownfrequency. In some configurations, EM signals may be initially output byan antennae (also mounted on the vehicle) and/or further propagated bypatterned resonant circuits (referred to herein as “resonators”, whichcan be 3D printed onto the tire body plies) mounted within one or morewheel wells. In this way, attenuation and/or frequency shifts associatedwith respective SRRs relative to the emitted signal may beelectronically observed and analyzed to gauge current environmentalconditions. In addition, changes in the RF resonant frequency (orfrequencies) may be observed and compared to known and discretecalibration points to determine tire air pressure as measured at one ormore defined detection points on the vehicle's bodywork at a givenmoment in time.

Conventional use of tires, such as that encountered during on-roaddriving for most road tires, or off-for off-road tires, can cause slightdeformations of portions of the tire, which can cause a change in thenatural RF resonance frequency of a respective SRR at the time y being‘pinged’ by a RF signal). Such changes in the natural resonancefrequencies (as associated with presently disclosed carbons formingvarious SRRs can be detected and compared to known calibration points todetermine conditions inside the tire. Systems employing antennae incombination with the presently disclosed SRRs incorporated within tireplies may accommodate both the sensing of tire ply property changes andreporting-out to associated telemetry equipment in the vehicle.

Presently disclosed SRRs may be tuned to detect even minute changes inphysical properties of respective tire plies, including changes due toair pressure on a vehicle skin, or due to any external application offorces in/on a tire. Such changes can be detected by “pinging” (e.g.,e.g., emitting, and later observation and analysis of RF signals) forthen processing the unique set of detected properties (e.g., the“signature”) of a given tire ply, tread layer, or other surface orregion as demonstrated by, for example, frequency domain return. Variousmechanisms for calibrating an observed signal signature and processing areturn signature are discussed. Methods for fabrication of a tire withpassive embedded sensors in the form of tuned carbon structures thatinteract with the elastomer are disclosed. For example, mechanisms usedfor making a tire from multiple plies may influences SRR naturalresonance frequency behavior. In addition, tires may be constructedincluding multiple tire plies, each tire ply incorporating a distincttuned carbon having a unique tuned carbonaceous microstructure, whichmay be micron-sized, or alternatively in any one or more of thenanometer, micro, even meso-particle sizes up to the millimeter (mm)level.

Disclosed SRRs may permit for self-powered signatures from resonance inthe GHz and MHz range as made possible by tribological power generators(e.g., generating electric current upon, for example, rotation of avehicle tire and its repeated friction and/or contact with the pavementor ground). Such tribological components can be integrated or otherwiseincorporated within multiple steel belts in between elastomer layers inone or more vehicle tire plies. In this way, the SRRs may be charged(and/or powered) by the triboelectric generator for the resonator toresonate (and thus emit RF signals) and discharge. The resonator can beconfigured to accommodate repeated charge-discharge cycles and be in anyone or more of a variety of shapes and/or patterns, including ovals thathave an inherent resonant value or properties (based on its formativematerials and/or construction).

Changes in the shape or orientation of the resonator may result in acorresponding change of any associated resonation constants. As aresult, any change in tire physical properties due to deformation, e.g.,under static conditions like internal tire pressure, or under dynamicconditions such as those encountered while running over Bots Dots, canchange the shape or orientation of a respective SRR. Different resonatorpatterns (e.g., in addition, or the alternative, to SRRs) can be used torespond with greater sensitivity to one type of deformation over another(such as referring to lateral deformation encountered while movingaround a curve compared to vertical motion encountered while runningover gravel or a rough surface). In addition to configurations whereSRRs change in signal response behavior based on tire deformation, SRRsmay also electronically communicate with other signal attenuationdetection capabilities, e.g., as associated with a digital signalprocessing, DSP, computer chip and/or transducers placed within thewheel well, or even within the rim, of a wheel. DSP may function withexternal transceiver (a semiconductor chip) for both stimulus andresponse; while option. SRRs may also communicate with tribologicalgenerators incorporated in individual tire plies and demonstrateresonance behavior that can detected by an external receiver.

FIG. 1 is a schematic diagram a vehicle condition detection system 1A00e.g., intended to be equipped onto a vehicle such as an automobileand/or truck. The vehicle condition detection system 1A00 may includesensors, such as tuned RF resonance components 108 (e.g., split-ringresonators, such as that shown in FIG. 8 ). Each of the as tuned RFresonance components 108 may be formed from multiple carbon-basedmicrostructural materials, aggregates, agglomerations, and/or the likesuch as those disclosed in U.S. Pat. No. 11,198,611. The tuned RFresonance components 108 can be incorporated into any one or more ofbelt sensors 104, hose sensors 105, tire sensors 106, and transceiverantennas 102 on a vehicle, such as a conventional driver-drivenautomobile or a fully-autonomous transport pod or vehicle capable ofoperating to move vehicle occupants without a human driver.

The tuned RF resonance components 108 can be configured toelectronically and/or wirelessly communicate, such as by measurement ofsignal frequency shift or attenuation, with any one or more of atransceiver 114, a vehicle central processing unit 116, a vehicle sensordata receiving unit 118, a vehicle actuators control unit 120, andactuators 122 including doors, windows, locks 125, engine controls 126,navigation/heads-up displays 128, suspension control 129, and an airfoiltrim 130. The tuned RF resonance components 108 can cause a shift inobserved frequencies of emitted RF signals (referred to as a“frequency-shift”, implying any change in frequency) via emitted RFsignals 110 and/or returned RF signals 112 with the transceiver 114.Reference to the returned RF signals 112 corresponding to emitted RFsignals 110 may refer to the electronic detection of frequency shift orattenuation of the emitted RF signals 110 relative to one or more of thetuned RF resonance components 108 integrated into any one or more of thebelt sensors 104 and/or the like (e.g., rather than an actual physicalreflection or return of a signal from a sensor). The emitted RF signals110 and the returned RF signals 112 can be in communication with (andtherefore also assessed by) any one or more of the vehicle centralprocessing unit 116, the vehicle sensor data receiving unit 118, thevehicle actuators control unit 120, and/or the actuators 122. Thevehicle condition detection system 100 can be implemented using anysuitable combination of software and hardware.

Any one or more of the depicted various sensors of the vehicle conditiondetection system 100 can be formed of carbon-based microstructures tunedto achieve a specific RF resonance behavior upon being “pinged”(referring to being hit or otherwise contacted by) emitted RF signals.The vehicle condition detection system 100 (or any aspect thereof) canbe configured to be implemented in any conceivable vehicle useapplication, area, or environment, such as during inclement weatherconditions including sleet, hail, snow, ice, frost, mud, sand, debris,uneven terrain, water and/or the like.

The tuned RF resonance components 108 can be disposed around and/or onthe vehicle (such as within the cabin, engine compartment, or the trunk,or on the body of the vehicle). As shown in FIG. 1A, the tuned RFresonance components can include belt sensors 104, hose sensors 105,tire sensors 106, and transceiver antennas 102, any one or more of whichcan be implemented in modern vehicles during their production, or(alternatively) retro-fitted to pre-existing vehicles, regardless oftheir age and/or condition. The tuned RF resonance components 108 can beformed, in part, using readily available materials such as fiberglass(such as, for airfoils) or rubber (such as, for tires) or glass (suchas, for windshields). These conventional materials can be combined withcarbon-based materials, growths, agglomerates, aggregates, sheets,particles and/or the like, such as those self-nucleated in-flight in areaction chamber or reactor from a carbon-containing gaseous species andformulated to: (1) improve the mechanical (such as tensile, compressive,shear, strain, deformation and/or the like) strength of a compositematerial in which they are incorporated; and/or, (2) to resonate at aparticular frequency or set of frequencies (within the range of 10 GHzto 100 GHz). Variables that dominate RF resonance properties andbehavior of a material can be controlled independently from thevariables responsible for control of material strength.

Radio Frequency (RF) based stimulation (such as that emitted by thetransceiver 114 or emitted by a resonator) can be used to emit RFsignals to the tuned RF resonance components 108, the actuators 122(and/or the like, such as sensors implemented in or on the tuned RFresonance components 108) to detect their respective resonance frequencyor frequencies, as well as frequency shifts and patterns observed in theattenuation of emitted signals (which may be affected by internal orexternal conditions). For example, if a tuned RF resonance component(such as the tire sensors 106) has been specially prepared (referred toas being “tuned”) to resonate at a frequency of approximately 3 GHz,then the tire sensors 106 can emit sympathetic resonance or sympatheticvibrations (referring to a harmonic phenomenon wherein a formerlypassive string or vibratory body responds to external vibrations towhich it has a harmonic likeness) when stimulated by a 3 GHz RF signal.

These sympathetic vibrations can occur at the stimulated frequency aswell in overtones or sidelobes deriving from the fundamental 3 GHz tone.If a tuned resonance component (of the tuned RF resonance components108) has been tuned to resonate at 2 GHz, then when the tuned resonancecomponent is stimulated by a 2 GHz RF signal, that tuned resonancecomponent will emit sympathetic vibrations as so described. Thesesympathetic vibrations will occur at the stimulated frequency as well asin overtones or sidelobes (in engineering, referring to local maxima ofthe far field radiation pattern of an antenna or other radiation source,that are not the main lobe) deriving from the fundamental 2 GHz tone.Many additional tuned resonance components can be situated proximally toan RF emitter. An RF emitter might be controlled to first emit a 2 GHzping, followed by a 3 GHz ping, followed by a 4 GHz ping, and so on.This succession of pings at different and increasing frequencies may bereferred to as a “chirp.”

Adjacent tire plies (such as those in contact with each other) within atire body, such as that generally shown by FIGS. 3F1-3F2, can havevarying concentration levels or configurations of carbon-basedmicrostructures to define sensors incorporated within that (referring tothe respective) tire body ply and/or tread layer to resonate at varyingdistinct frequencies that are not harmonic with one-another. That is,non-harmonic plies can ensure a distinct and easily recognizabledetection of a particular tire body ply and/or tread layer (or othersurface or material) relative to others with minimal risk of confusiondue to signal interference caused by (or otherwise associated with)harmonics.

The transceiver 114 (and/or a resonator, not shown in FIG. 1A) can beconfigured to transmit the emitted RF signals 110 to any one or more ofthe tuned RF resonance components 108 to digitally recognize frequencyshift and/or attenuation of the returned RF signals 112 from any one ormore of the tuned RF resonance components 108. Such “returned” signals112 can be processed into digital information that can be electronicallycommunicated to a vehicle central processing unit 116, that interactswith a vehicle sensor data receiving unit 118 and/or a vehicle actuatorscontrol unit 120, which send further vehicle performance related signalsbased on sensor data received. The returned signals 1120 can at leastpartially control the actuators 122. That is, the vehicle actuatorscontrol unit 120 can control the actuators 122 to operate any one ormore of the doors, windows, locks 124, the engine controls 126, thenavigation/heads-up displays 128, the suspension control 129, and/or theairfoil trim 130 according to feedback received from the vehicle sensordata receiving unit 118 regarding vehicle component wear or degradationas indicated by the tuned RF components in communication with thetransceiver 114.

Detection of road debris and inclement weather conditions uponmonitoring behavior (such as frequency shift and/or attenuation) of thereturned RF signals 111 can, for example, result in the actuators 122triggering a corresponding change in the suspension control 129. Suchchanges can, for example, include softening suspension settings toaccommodate driving over the road debris, while later tighteningsuspension settings to accommodate enhanced vehicle responsiveness asmay be necessary to travel during heavy rain (and thus low traction)conditions. The variations of such control by the vehicle actuatorscontrol unit 120 are many, where any conceivable condition exterior tothe vehicle can be detected by the transceiver (as demonstrated byfrequency shifting and/or attenuation of the emitted RF signals 110and/or the returned RF signals 112).

Any of the tuned RF resonance components 108 forming the describedsensors can be tuned to resonate when stimulated at particularfrequencies, where a defined shift in frequency or frequencies (ascaused by the carbon-based microstructures) can form one or more signalsignatures indicative of the material, or condition of the material,into which the sensor is incorporated.

Time variance or deviation (TDEV) (referring to the time stability ofphase x versus observation interval r of the measured clock source; thetime deviation thus forms a standard deviation type of measurement toindicate the time instability of the signal source) of frequency shiftsin the returned RF signals 112 (such as that shown in a signalsignature) can correspond to time variant changes in the environment ofthe sensor and/or time variant changes in the sensor itself.Accordingly, signal processing systems (such as any one or more of thevehicle central processing unit 116, the vehicle sensor data receivingunit 118, and/or the vehicle actuators control unit 120, etc.) can beconfigured to analyze signals (such as the emitted RF signals 110 andreturned RF signals 112) associated with the sensors according to TDEVprinciples. Results of such analysis (such as a signature analysis) canbe delivered to the vehicle central processing unit 116, which (in turn)can communicate commands to the vehicle actuators control unit 120 forappropriate responsive action. In some configurations such responsiveaction by the actuators 122 can involve at least some human driverinput, while in other configurations the vehicle condition detectionsystem 100 can function entirely in a self-contained manner allowing fora so-equipped vehicle to address component performance issues as theyarise in an entirely driverless setting. In addition, the vehiclecentral processing unit 116 may electronically communicate with one ormore upstream components (e.g., computational equipment associated withracing applications housed in stationary areas) and/or a racing missioncontrol unit 119 responsible for intake and/or processing of all dataassociated with the tuned RF resonance components 108.

FIG. 2 shows a block diagram of a signal processing system 200, whichcan include surface sensors 260 and embedded sensors 270, any one ormore of which may electronically communicate with the other concerningenvironmental changes 250 for a so-equipped vehicle (referring to avehicle equipped with the surface sensors 260 and the embedded sensors270). The signal processing system 200 may also include a transceiver214, a signature analysis module 254, and a vehicle central processingunit 216, any one or more of which is in electronic communication withthe other.

In some implementations, embedded sensors 270 (which can be embeddedwithin materials such as tire plies) can employ and/or be powered byself-powered telemetry including tribological energy generators (notshown in FIG. 2 ) also incorporated within the material enclosed therespective sensor. Accordingly, the tribological energy generators cangenerate usable electric current and/or power by harvesting staticcharge buildup between, for example, a rotating tire or wheel and thepavement it contacts, to power a resonant circuit (to be described infurther detail herein), which can then resonate to emit a RF signal at aknown frequency. As a result, an externally-mounted transceiver unit(such as that mounted within each wheel well of a vehicle) can emit RFsignals which are further propagated by the resonant circuits that aretribologically-powered and embedded in the plies of a tire body in thisconfiguration. Frequency shifts and/or attenuation of the magnitude ofthe emitted signals are likewise received and analyzed, for example, bya signature analysis module 254 and/or a vehicle central processing unit216.

Self-powered telemetry (referring to collection of measurements or otherdata at remote or inaccessible points and their automatic transmissionto receiving equipment for monitoring) can be incorporated in vehicletires. Self-powering telemetry, as referred to herein, includesexploiting tribological charge generation inside a tire, storage of thatcharge, and later discharge of the stored charge to or through aresonant circuit, to make use of the “ringing” (referring to oscillationof the resonant circuit responsible for further emission of RF signals)that occurs during discharge of the resonant circuit (referring to anelectric circuit consisting of an inductor, represented by the letter L,and a capacitor, represented by the letter C, connected together, usedto generate RF signals at a particular frequency or frequencies).

Ping stimulus can be provided, generally, in one of two possibleconfigurations of the presently disclosed vehicle component weardetection systems, including reliance on signals or ‘pings’ generated bya stimulus source, such as a conventional transceiver, located outsidethe tire (or other vehicle component intended for monitoring regardingwear from ongoing use) such as being incorporated within each wheel wellof a so-equipped vehicle; or usage of an intra-tire (referring to alsobeing embedded in the tire plies, similar to the sensors havingcarbon-based microstructures) tribological energy generation devicesthat harvest energy resultant from otherwise wasted frictional energybetween the rotating wheel and/or tire and the ground or pavement incontact therewith. Tribology, as commonly understood and as referred toherein, implies the study of the science and engineering of interactingsurfaces in relative motion. Such tribological energy generation devicescan provide electrical power to intra-tire resonance devices which inturn self-emit tire property telemetry.

Either of the above-discussed two ‘ping’ stimulus generators orproviders can have complex resonance frequencies (CRf) componentsranging from approximately 10 to 99 GHz (due, for example, resonancefrequency of small dimensions of structures like graphene platelets) aswell as lower frequency resonance in Khz range due to the relativelymuch larger dimensions of the discussed intra-tire resonance. Generally,CRf can be equated to a function of elastomer component innate resonancefrequency, carbon component innate resonance frequency, ratio/ensembleof the constituent components, and the geometry of the intra-tireresonance device.

The signal processing system 200 functions to analyze a signal signature(defined by digitally observing frequency shifting and/or attenuation ofany one or more of the emitted RF signals 210 and/or returned RF signals212) once sensors formed of carbon-based microstructures have beenstimulated. As a result of stimulation with a chirp signal sensor thatresonate at one of the chirp/ping frequencies “respond” by resonating ator near its corresponding tuned frequency, shifting the emittedfrequency, and/or attenuating the amplitude of the emitted signal. Whenan environmental change (such as that resulting in the wear of a tirebody ply and/or tread layer) occurs while the chirp/ping is emitted,“returned” signals can monitored for variations in modulation—eitherhigher or lower than the tuned frequency. Accordingly, the transceiver214 can be configured to receive returned RF signals 212 that arerepresentative of the surfaces that they are pinged on or against, etc.

The foregoing chirp/ping signals can be emitted (such as by non-audibleRF signal, pulse, vibration and/or the like transmission) by thetransceiver 214. Also, the “return” signals can be received by thetransceiver 214. As shown, chirp signals can occur in a repeatingsequence of chirps (such as, the emitted RF signals 210). For example, achirp signal sequence might be formed of a pattern comprising a 1 GHzping, followed by a 2 GHz ping, followed by a 3 GHz ping, and so on. Theentire chirp signal sequence can be repeated in its entiretycontinuously. There can be brief periods between each ping such that thereturned signals from the resonant materials (returned RF signals 212)can be received immediately after the end of a ping. Alternatively, orin addition, signals corresponding to ping stimulus and signals of theobserved “response” can occur concurrently and/or along the same generalpathway or route. The signature analysis module can employ digitalsignal processing techniques to distinguish signals of the observed“response” from the ping signals. In situations where the returnedresponse comprises energy across many different frequencies (such as,overtones, sidelobes, etc.), a notch filter can be used to filter thestimulus. Returned signals that are received by the transceiver can besent to the signature analysis module 254, which in turn can sendprocessed signals to vehicle central processing unit 216. The foregoingdiscussion of FIG. 2 includes discussion of sensors formed ofcarbon-containing tuned resonance materials and can also refer tosensing laminates as well.

Disclosed sensors may be incorporated into tire layers, e.g., includinglayers of resin can be layered interstitially between additional layersof carbon fiber within tire plies. Each layer of carbon-containing resincan be formulated differently to resonate at a different expected ordesired tuned frequency. The physical phenomenon of material resonationcan be described with respect to a corresponding molecular composition.For example, a layer having a first defined structure, such as a firstmolecular structure will resonate at a first frequency, whereas a layerhaving a second, different molecular structure can resonate at a second,different frequency

Material having a particular molecular structure and contained in alayer will resonate at a first tuned frequency when that layer is in alow energy state and will resonate at a second different frequency whenthe material in the layer is in an induced higher-energy state. Forexample, material in a layer that exhibits a particular molecularstructure can be tuned to resonate at a 3 GHz when the layer is in anatural, undeformed, low energy state. In contrast, that same layer canresonate at 2.95 GHz when the layer is at least partially deformed fromits natural, undeformed, low energy state. As a result, this phenomenoncan be adjusted to accommodate the needs for detecting, with a highdegree of fidelity and accuracy, even the most minute aberration to, forexample, a tire surface contacting against a road surface such aspavement and experiencing enhanced wear at a certain localized region ofcontact. Race cars racing on demanding race circuits (referring tohighly technical, windy tracks featuring tight turns and rapidelevational changes) can benefit from such localized tire wear ordegradation information to make informed tire-replacement decisions,even in time-sensitive race-day conditions.

The frequency-shifting phenomenon referred to above (such astransitioning from resonating at a frequency of 3 GHz to 2.95 GHz) isshown and discussed with reference to FIG. 2 . FIG. 2 depicts afrequency-shifting phenomenon as exhibited in a sensing laminate thatincludes carbon-containing tuned resonance materials. Atoms emitelectromagnetic radiation at a natural frequency for a given element.That is, an atom of a particular element has a natural frequency thatcorresponds to characteristics of the atom. For example, when a Cesiumatom is stimulated, a valence electron jumps from a lower energy state(such as, a ground state) to a higher energy state (such as, an excitedenergy state). When the electron returns to its lower energy state, itemits electromagnetic radiation in the form of a photon. For Cesium, thephoton emitted is in the microwave frequency range; at 9.192631770 THz.Structures that are larger than atoms, such as molecules formed ofmultiple atoms also resonate (such as by emitting electromagneticradiation) at predictable frequencies. For example, liquid water in bulkresonates at 109.6 THz. Water that is in tension (such as, at thesurface of bulk, in various states of surface tension) resonates at112.6 THz. Carbon atoms and carbon structures also exhibit naturalfrequencies that are dependent on the structure. For example, thenatural resonant frequency of a carbon nanotube (CNT) is dependent onthe tube diameter and length of the CNT. Growing a CNT under controlledconditions to control the tube diameter and length leads to controllingthe structure's natural resonant frequency. According, synthesizing orotherwise “growing” CNTs is one way to tune to a desired resonantfrequency.

Other structures formed of carbon can be formed under controlledconditions. Such structures include but are not limited to carbonnano-onions (CNOs), carbon lattices, graphene, carbon-containingaggregates or agglomerates, graphene-based, other carbon containingmaterials, engineered nanoscale structures, etc. and/or combinationsthereof, any one or of which being incorporated into sensors of vehiclecomponents according to the presently disclosed implementations. Suchstructures can be formed to resonate at a particular tuned frequencyand/or such structures can be modified in post-processing to obtain adesired characteristic or property. For example, a desired property suchas a high reinforcement value can be brought about by selection andratios of combinations of materials and/or by the addition of othermaterials. Moreover, co-location of multiples of such structuresintroduces further resonance effects. For example, two sheets ofgraphene may resonate between themselves at a frequency that isdependent on the length, width, spacing, shape of the spacing and/orother physical characteristics of the sheets and/or their juxtapositionto each other.

As is known in the art, materials have specific, measurablecharacteristics. This is true for naturally occurring materials as wellas for engineered carbon allotropes. Such engineered carbon allotropescan be tuned to exhibit physical characteristics. For example, carbonallotropes can be engineered to exhibit physical characteristicscorresponding to: (a) a particular configuration of constituent primaryparticles; (b) formation of aggregates; and (c) formation ofagglomerates. Each of these physical characteristics influence theparticular resonant frequencies of materials formed using correspondingparticular carbon allotropes.

In addition to tuning a particular carbon-based structure for aparticular physical configuration that corresponds to a particularresonant frequency, carbon-containing compounds can be tuned to aparticular resonant frequency (or set of resonant frequencies). A set ofresonant frequencies is termed a resonance profile. Carbon-containingmaterials (such as those including carbon-based microstructures) tunedto demonstrate a specific resonance frequency upon being pinged by a RFsignal can be tuned to exhibit a particular resonance profile bytailoring specific compounds that make up the materials to haveparticular electrical impedances. Different electrical impedances inturn correspond to different frequency response profiles.

Impedance describes how difficult it is for an alternating (AC) currentto flow through an element. In the frequency domain, impedance is acomplex number having a real component and an imaginary component due tothe structures behaving as inductors. The imaginary component is aninductive reactance (the opposition of a circuit element to the flow ofcurrent due to that element's inductance or capacitance; largerreactance leads to smaller currents for the same voltage applied)component X_(L), which is based on the frequency ƒ and the inductance Lof a particular structure:X _(L)=2πƒL  (Eq. 1)

As the received frequency increases, the reactance also increases suchthat at a certain frequency threshold the measured intensity (amplitude)of the emitted signal can attenuate. Inductance L is affected by theelectrical impedance Z of a material, where Z is related to the materialproperties of permeability μ and permittivity c by the relationship:

$\begin{matrix}{Z = {\sqrt{\frac{\mu^{\prime} + {j\mu^{''}}}{\varepsilon^{\prime} + {j\varepsilon^{''}}}} = \sqrt{\frac{\mu_{0}}{\varepsilon_{0}},}}} & \left( {{Eq}.2} \right)\end{matrix}$

Thus, tuning of material properties changes the electrical impedance Z,which affects the inductance L and consequently affects the reactanceX_(L).

Carbon-containing structures, such as those disclosed in U.S. Pat. No.10,428,197, incorporated herein by reference in its entirety, withdifferent inductances can demonstrate different frequency responses(when used to create sensors for the aforementioned systems). That is, acarbon-containing structure with a high inductance L (being based onelectrical impedance Z) will reach a certain reactance at a lowerfrequency than another carbon-containing structure with a lowerinductance.

The material properties of permeability, permittivity and conductivitycan also be considered when formulating a compound to be tuned to aparticular electrical impedance. Still further, it is observed that afirst carbon-containing structure will resonate at a first frequency,whereas second carbon-containing structure will resonate at a secondfrequency when that structure is under tension-inducing conditions, suchas when the structure is slightly deformed (such as, thereby slightlychanging the physical characteristics of the structure).

Example carbon-containing structures that may resonate at a firstfrequency, which can be correlated to an equivalent electrical circuitcomprising a capacitor C₁ and an inductor L₁. The frequency f₁ is givenby the equation:

$\begin{matrix}{f_{1} = \frac{1}{2\pi\sqrt{L_{1}C_{1}}}} & \left( {{Eq}.3} \right)\end{matrix}$

Deformation of the carbon-containing structure may, in turn, change theinductance and/or capacitance of the structure. The changes can becorrelated to an equivalent electrical circuit comprising a capacitor C₂and an inductor L₂. The frequency f₂ is given by the equation:

$\begin{matrix}{f_{2} = \frac{1}{2\pi\sqrt{L_{2}C_{2}}}} & \left( {{Eq}.4} \right)\end{matrix}$

FIG. 3 illustrates a signature classification system 300 that processessignals received from sensors formed of carbon-containing tunedresonance materials. The signature classification system 300 can beimplemented in any physical environment or weather condition. FIG. 3relates to incorporating tuned resonance sensing materials intoautomotive components for classifying signals (such as, signatures)detected by, classified and/or received from sensors installed invehicles. A ping signal of a selected ping frequency is transmitted atoperation 302. The ping signal generation mechanism and the pingtransmission mechanism can be performed by any known techniques. Forexample, a transmitter module can generate a selected frequency of 3GHz, and radiate that signal using an antenna or multiple antennae. Thedesign and location of the tuned antenna (such as mounted on and/orwithin any one or more of the wheel wells or a vehicle) can correspondto any tuned antenna geometry, material and/or location such that thestrength of the ping is sufficient to induce (RF) resonance in proximatesensors. Several tuned antennae are disposed upon or within structuralmembers that are in proximity to corresponding sensors. As such, when aproximal surface sensor is stimulated by a ping, it resonates back witha signature. That signature can be received (operation 304) and storedin a dataset comprising received signatures 310. A sequence oftransmission of a ping, followed by reception of a signature, can berepeated in a loop.

The ping frequency can be changed (operation 308) in iterative passesthrough the loop. Accordingly, as operation 304 is performed in theloop, operation 304 can store signatures 312, including a firstsignature 3121, a second signature 3122, up to an N^(th) signature 312_(N). The number of iterations can be controlled by decision 306. Whenthe “No” branch of decision 306 is taken (such as, when there are nofurther additional pings to transmit), then the received signatures canbe provided (operation 314) to a digital signal processing module (suchas, an instance of signature analysis module 154 shown in FIG. 1B). Thedigital signal processing module classifies the signatures (operation316) against a set of calibration points 318. The calibrations pointscan be configured to correspond to particular ping frequencies. Forexample, calibration points 288 can include a first calibration point288 ₁ that can correspond to a first ping and first returned signaturenear 3 GHz, a second calibration point 2882 that can correspond to asecond ping and second returned signature near 2 GHz, and so on for anyinteger value “N” calibration points.

At operation 320, classified signals are sent to a vehicle centralprocessing unit (such as, the vehicle central processing unit 116 ofFIG. 1B). The classified signals can be relayed by the vehicle centralprocessing unit to an upstream repository that hosts a computerizeddatabase configured to host and/or run machine learning algorithms.Accordingly, a vast amount of stimulus related to signals, classifiedsignals, and signal responses can be captured for subsequent dataaggregation and processing. The database can be computationallyprepared, referring to as being “trained”, provided a given set ofsensed measurements that can be correlated to conditions or diagnosesrelated to vehicular performance, such as tire degradation due torepeated use. Should, during the operation of the vehicle, the measureddeflection (such as, air pressure) of a particular portion of an airfoilcomponent differ from the measured deflection (such as, air pressure) ofa different portion of the airfoil component, a potential diagnosis maybe that one tire is underinflated and therefore causing vehicle rideheight to be non-uniform, resulting in airflow over, on, and/or aroundthe vehicle to demonstrate proportionate non-uniformities, as detectedby deflection on the airfoil component. Other potential conditions ordiagnoses can be determined by the machine learning system as well. Theconditions and/or diagnoses and/or supporting data can be returned tothe vehicle to complete a feedback loop. Instrumentation in the vehicleprovides visualizations that can be acted upon (such as, by a driver orby an engineer).

FIG. 4 illustrates various physical characteristics or aspects (tirecondition parameters 400) pertaining to incorporating tuned resonancesensing materials into automotive components (such as tires). Here, thefigure is presented with respect to addressing deployment of survivablesensors in tires, including non-pneumatic tires as well as pneumatictires. The construction of the tires may correspond to radial tires,bias ply tires, tubeless tires, solid tires, run-flat tires, etc. Tiresmay be used in any sorts of vehicles and/or equipment and/or accessoriespertaining to vehicles. Such vehicles may include aircraft, all-terrainvehicles, automobiles, construction equipment, dump trucks, earthmovers,farm equipment, forklifts, golf carts, harvesters, lift trucks, mopeds,motorcycles, off-road vehicles, racing vehicles, riding lawn mowers,tractors, trailers, trucks, wheelchairs, etc. The tires may, in additionor alternative to that presented, be used in non-motorized vehicles,equipment and accessories such as bicycles, tricycles, unicycles,lawnmowers, wheelchairs, carts, etc.

The parameters shown in FIG. 4 are as an example, and other variants mayexist or otherwise be prepared to target specific desirable performancecharacteristics of many conceivable end-use scenarios, including trucktires designed to offer increased longevity (at the potential expense ofroad adhesion), or soft racing tires designed to provide maximum roadadhesion (at the potential expense of lifespan).

Various carbon structures are used in different formulations with othernon-carbon materials integrated into tires, which then undergomechanical analysis to determine their respective characteristics of thetires. Some of these characteristics can be determined empirically bydirect testing, while other characteristics are determined based onmeasurements and data extrapolation. For example, rolling uniformity canbe determined by sensing changes in force when the tire is subjected torolling over a uniform surface such as a roller, whereas tread life isbased on an abrasion test over a short period, the results of whichshort term test are extrapolated to yield a predicted tread life value.

More tire characteristics can be measured, but some of these measurementtechniques can be physically destructive to the tire, and thus measuredat a desired point in the life of the tire. In contrast, usingsurvivable sensors embedded in tires allows for such otherwisedestructive measurements to be made throughout the entire lifetime ofthe tire. For example, detection of response signals based on RF signalspinged against sensors e embedded in tires can be used for such sensing.Moreover, each body ply and/or tread layer of a tire can, as discuss,include durable (also referred to as “survivable”) sensors that aretuned to resonate at a particular frequency.

Ply used in a tire can be formulated to combine carbon-containingstructures with other materials to achieve a particular materialcomposition that exhibits desired performance (such as handling andlongevity) characteristics. The natural resonance frequency (orfrequencies) of the particular material composition can be subjected tospectral analysis to develop a spectral profile for the particularmaterial composition. This spectral profile can be used as a calibrationbaseline for that material. When the body ply and/or tread layer of thetire undergoes deformation, the spectral profile changes, which spectralprofile changes can be used as additional calibration points. Many suchcalibration points can be generated by testing, and such calibrationpoints can in turn be used to gauge deformation.

Analysis of the spectral response results in quantitative measurementsof many tire parameters. The tire parameters that can be determined fromsignature analysis, for example, can include tread life 422, handling ata first temperature 428, handling at a second temperature 426, rollingeconomy at a first temperature 430, rolling economy at a secondtemperature 432, rolling uniformity 436, and braking uniformity 438.

Responses, such as those spectrally represented based on return pingsignals received from sensors embedded in materials in tire ply, can berepresentative of the deformation observed. That is, a certain type oftire deformation will correspond with a certain type of specificresponse, such that a mapping between responses or response types can bedone to degradation types. Moreover, time-variant changes in thespectral response of a tire as it undergoes in-situ deformation can beused to determine many ambient conditions. In tires that are constructedusing multiple ply, each body ply and/or tread layer can be formulatedto exhibit a particular tuned frequency or range of frequencies. Forexample, FIG. 5 shows a schematic diagram for constructing a tire frommultiple ply, each of which has as different a particular tunedfrequency or range of frequencies.

FIG. 5 depicts a schematic diagram 500 for fine-adjustment, or tuning,of multiple body plies and/or tread layers of a tire by selectingcarbon-containing tuned resonance materials for incorporation into atire assembly or structure, which can be implemented in any environment.FIG. 5 illustrates how to mix different carbons into tire compositeformulations that are in turn assembled into a multi-ply tire. Theresulting multi-ply tire exhibits the various resonance-sensitive andfrequency-shifting characteristics.

Multiple reactors (such as, reactor 552 ₁, reactor 552 ₂, reactor 552 ₃,and reactor 552 ₄) each produce (or otherwise transport or provide) aparticular carbon additive/filler to the network that is tuned to yielda particular defined spectral profile. The carbon additives (such as,first tuned carbons 554, second tuned carbons 556, third tuned carbons558, and fourth tuned carbons 560) can mixed with other (carbon-based ornon-carbon based) compositions 550. Any known techniques can be used tomix, heat, pre-process, post-process or otherwise combine the particularcarbon additives with the other compositions. Mixers (such as, mixer 562₁, mixer 562 ₂, mixer 562 ₃, and mixer 562 ₄) are presented to show howdifferent tuned carbons can be introduced into various components of atire. Other techniques for tire assembly may involve other constructiontechniques and/or other components that comprise the tire. Any knowntechniques for multi-ply tires can be used. Moreover, the spectralprofile of a particular body ply and/or tread layer (such as a group ofbody plies and/or tread layers 568, including a body ply and/or treadlayer 568 ₁, a body ply and/or tread layer 568 ₂, a body ply and/ortread layer 568 ₃, and a body ply and/or tread layer 568 ₄) can bedetermined based on the characterization of a particular body ply and/ortread layer formulation. For example, based on a stimulus and responsecharacterization, a first body ply and/or tread layer formulation (suchas, body ply and/or tread layer formulation 564 ₁) might exhibit a firstspectral profile, whereas a second body ply and/or tread layerformulation (such as, body ply and/or tread layer formulation 564 ₂)might exhibit a second spectral profile.

The resulting different formulations (such as, body ply and/or treadlayer formulation 564 ₁, body ply and/or tread layer formulation 564 ₂,body ply and/or tread layer formulation 564 ₃, and body ply and/or treadlayer formulation 564 ₄), each of which body ply and/or tread layerexhibits a corresponding spectra profile, are used in the different bodyply and/or tread layer that are formed into a tire assembly 566.

FIG. 6 shows a second set of example condition signatures 600 that areemitted from tires formed of layers of carbon-containing tuned resonancematerials. The example condition signatures 600 or any aspect thereofmay be emitted in any environment. FIG. 9 illustrates multiple body plyand/or tread layer (such as, body ply and/or tread layer #1, body plyand/or tread layer #2, and body ply and/or tread layer #3) of a newtire. The term “ply”, as used in this example and elsewhere withreference to any one or more of the presented implementations, can referto a ply or layer within a body of the tire, or—alternatively— a layerof the tire tread protruding radially outward away from the body of thetire intended for contact with hard pavement, or the earth for off-roadtires). In example, the first body ply and/or tread layer is formulated(referring to being created with a specific formula) with tuned carbonssuch that the first body ply and/or tread layer resonates at 1.0 GHzwhen stimulated with a 1.0 GHz ping stimulus (such as, first ping 602).Similarly, the second body ply and/or tread layer is formulated withtuned carbons such that the second body ply and/or tread layer resonatesat 2.0 GHz when stimulated with a 2.0 GHz ping stimulus (such as, secondping 604). Further, the third body ply and/or tread layer is formulatedwith tuned carbons such that the third body ply and/or tread layerresonates at 3.0 GHz when stimulated with a 3.0 GHz ping stimulus (suchas, third ping 606). As shown by first response 608, second response610, and third response 614, all three-body ply and/or tread layer areresponsive at their respective tuned frequencies.

A transceiver antenna can be positioned in and/or on the wheel well ofthe corresponding tire. Systems handling any such generated responsesignals can be configured to distinguish from other potential responsesarising from the other surfaces, such as the remaining non-target tiresof the vehicle, for example. For example, even though the right fronttire mounted on the right front wheel of the vehicle might respond to aping that is emitted from a transceiver antenna located in the leftfront wheel well of the vehicle, the response signal from the rightfront tire will be significantly attenuated (and recognized as such) ascompared to the response signals from the left front tire of thevehicle.

When the transceiver antenna is located in the wheel well of acorresponding tire, the response from the corresponding tire will beattenuated with respect to the ping stimulus. For example, the responsefrom the corresponding tire can be attenuated with respect to the pingstimulus by 9 decibels (−9 dB) or more or can be attenuated with respectto the ping stimulus by 18 decibels (−18 dB) or more or can beattenuated with respect to the ping stimulus by 36 decibels (−36 dB) ormore or can be attenuated with respect to the ping stimulus by 72decibels (−72 dB) or more. In some cases, a ping signal generator isdesigned to be combined with a transceiver antenna located in the wheelwell so as to cause the ping response of a corresponding tire to beattenuated by not more than 75 dB (−75 dB).

FIG. 7 depicts a third set of example condition signatures 700 that areemitted from tires after wear-down of some of the carbon-containingtuned resonance materials. As an option, one or more variations ofexample condition signatures 700 or any aspect thereof may beimplemented in the context of the architecture and functionality of theimplementations described herein. The example condition signatures 700or any aspect thereof may be emitted in any environment.

In this example, the tire has undergone wear. More specifically, theoutermost body ply and/or tread layer has been worn away completely. Assuch, a ping stimulus at 1.0 GHz would not result in a response from theoutermost ply. This is shown in the chart as a first responseattenuation 702. As the tire continues to undergo tread wear, pingresponses from the next body ply and/or tread layer and ping responsesfrom the next successive body ply and/or tread layer and so on will beattenuated, which attenuation can be used to measure total tread wear ofthe tire. As an alternative, the same tuned carbons can be used in allplies. The tread wear of the tire as well as other indications can bedetermined based on the returned signal signatures from the tire.

FIG. 8 is a top view of two layers, where each layer hosts a split ringresonator (SRR), e.g., forming an example split-ring resonator (SRR)configuration including two concentric SRRs. As used herein, split ringresonators (SRRs) consist of a pair of concentric rings, disposed on adielectric substrate, where each ring has slits (e.g., due to a printedpattern). When an array of SRRs is excited by means of a time varyingmagnetic field, the structure behaves as an effective medium withnegative effective permeability in a narrow band around the SRRresonance point. Many geometries are possible, e.g., such thatdimensions and/or spacings between each SRR including dimensions “a,”“r”, and/or “c” are selected to achieve particular correspondingspectral response. For example, “a” may be approximately 1 mm, “r” maybe 2 mm, and “c” may be approximately 0.6 mm. These dimensions maycorrespond to producing a desired and/or expected spectral response,e.g., resulting in a relatively wider and/or broader signal responserather than a narrow and/or notched response, facilitating improvedspectral analysis leading to improved cost-efficiency in using spectralanalysis tools (such as a spectrum analyzer). In addition, or thealternative, any of the dimensions may be further adjusted to achieveparticular desired end-result objectives, e.g., applications in racingcircuits compared to off-road applications, etc. One particular geometryinvolves gaps between concentric rings. Such gaps produce a capacitancewhich in combination with the inductance inherent in the pair ofconcentric rings introduces a change in the resonance of the ensemble.

A printable, sheet-oriented, cylinder-type, split ring resonator designcan be built out of any electrically-conducting materials, includingmetals, electrically-conducting non-metals, dielectric materials,semiconducting materials, etc. In addition to tuning based on theselection and/or treatment of electrically-conducting materials, splitring resonators can be tuned by varying the geometry such that theeffective permittivity accordingly tuned. Effective permittivity as afunction of the geometry of a split ring resonator is given in EQ 1.

$\begin{matrix}{\mu_{eff} = {1 - \frac{\frac{\pi r^{2}}{a^{2}}}{1 + \frac{2l\sigma_{1}i}{\omega r\mu_{0}} - \frac{3{lc}_{0}^{2}}{{\pi\omega}^{2}r^{3}{\ln\left( \frac{2c}{d} \right)}}}}} & {{EQ}.1}\end{matrix}$where a is the spacing of the cylinders, w is the angular frequency, μ0is the permeability of free space, r is the radius, d is the spacing ofthe concentric conducting sheets, l is a stacking length, c is thethickness of a ring, and a is the resistance of unit length of thesheets measured around the circumference.

In some situations, the value of a (e.g., the spacing of the cylindersof a cylindrical split ring resonator) can be made relatively small suchthat the concentric rings absorb EM radiation within a relatively narrowfrequency range. In other situations, the value of a can be maderelatively large such that the concentric rings each absorb EM radiationat frequencies that are separated by a wide range. In some situations,differently-sized SRRs can be disposed on different surfaces of thetire. In some situations, the differently-sized SRRs that are disposedon different surfaces of the tire can be used to take measurements oftire conditions (e.g., temperature, aging, wear, etc.).

In some embodiments, the materials that form the split ring resonatorare composite materials. Each SRR can be configured to any particulardesired tuned response to EM stimulation. At least inasmuch as SRRs aredesigned to mimic the resonance response of atoms (though on a muchlarger scale, and at lower frequencies), the larger scale of SRRs ascompared with atoms allows for more control over the resonance response.Moreover, SRRs are much more responsive than ferromagnetic materialsfound in nature. The pronounced magnetic response of SRRs carries withit a significant advantage over heavier, naturally occurring materials.

FIG. 9 illustrates a schematic diagram showing a complete tirediagnostics system and apparatus for tire wear sensing throughimpedance-based spectroscopy. A tire 900, such as a pneumatic rubbertire filled with air or nitrogen gas (N₂), can include traditional tirecomponents including a body 920, an inner liner 912, a bead fillerregion 922, a bead 916, one or more belt plies 904, 906, 908, and 910,tread 902, and impedance-based spectroscopy wear sensing printedelectronics 918 (alternatively sensors including carbon-basedmicrostructures for signal frequency shift and attenuation monitoring bya resonator embedded within any one or more of the belt plies 904-910).

As shown here, a wireless strain sensor can be placed on surfaces or onthe sides of the inner liner (or be embedded within) to monitor the tirecondition for automobile safety, (such as to detect damaged tires). Tiredeformation or strain monitoring can (indirectly) provide informationrepresentative of a degree of friction between the tires and contactingroad surfaces, which can then be used for the optimization of automobiletire control systems. The tire information can be wirelessly transmittedto a receiver positioned in the tire hub based on a resonant sensorplatform.

FIG. 10 illustrates a system 1000 for providing tire wear-relatedinformation transferred via telemetry into a navigation system andequipment for manufacturing printed carbon-based materials. The system1000 can function with any one or more of the presently disclosedsystems, methods, and materials, such as the sensors includingcarbon-based microstructures such that a redundant description of thesame is omitted. Impedance spectroscopy, also referred to asElectrochemical Impedance Spectroscopy (EIS), refers to a method ofimpedimetric transduction involving the application of a sinusoidalelectrochemical perturbation (potential or current) over a wide range offrequencies when measuring a sample, such as a sensor includingcarbon-based microstructures incorporated within one or more tire beltplies of a tire 1002. Printed carbon-based resonators 1004 can beincorporated within one or more tire components such as the tire beltplies, with each of the printed carbon-based resonators 1004 having thegeneral oval configuration shown, or some other shape or configurationtailored to achieve specific desirable resonance properties suitable forefficient and accurate vehicle component wear detection throughmonitoring of frequency shift and/or attenuation (such as a firstresponse attenuation indicative of the wear of a tire body ply and/ortread layer having a natural resonance frequency of approximately 1.0GHz).

An assembly of rollers 1010 capable of forming the printed carbon-basedresonators 1004 includes a repository 1012 (such as a vat) ofcarbon-based microstructures and/or microstructural material (such asgraphene), an anilox roller 1014 (referring to a hard cylinder, usuallyconstructed of a steel or aluminum core which is coated by an industrialceramic whose surface contains millions of very fine dimples, known ascells), a plate cylinder 1016, and an impression cylinder 1018. Inoperation, graphene extracted from the repository 1012 can be rolled,pressed, stretched, or otherwise fabricated by the rollers of theassembly of rollers 1010 into the printed carbon-based resonators 1004.No registration (referring to alignment) of the printed carbon-basedresonators 1004 may be needed for functioning of the system 1000.

As such, any combination of the aforementioned features can be used tomanufacture a tire that has a resonator (referring to actual or“equivalent” tank, LC and/or resonant circuit, where carbon-containingmicrostructures themselves can resonate in response to emitted RFsignals from a transceiver, and/or from energy supplied by an advancedenergy source, such that other sensors, disposed into or onto any one ormore components such as the tread, a ply or plies, an inner liner, etc.of the tire can demonstrate frequency-shifting or signal attenuationproperties or behavior. The described resonator is not necessarilyrequired to be embodied as an actual electrical and/or integratedcircuit (IC). The described resonator can be realized simply as tunedcarbon-containing microstructures, to thus avoid common deteriorationconcerns that may arise when implementing traditional discrete circuitryin decomposable materials, such as tire tread layers. Such resonatorscan resonate in response to an externally-supplied ‘ping’ (such as thatsupplied by a transceiver located in the wheel well of vehicle), or theresonator can respond to being charged by a co-located (referring towithin the same tire tread layer, but possibly at a different locationwithin that tire tread layer), self-powered, self-pinging capabilityfacilitated by any variations or any number of power or chargegenerators (such as thermoelectric generators, piezoelectric energygenerators, triboelectric energy generators, etc.).

At any time when the tire is rolling or otherwise undergoingdeformation, any of the described resonators (and other resonatorsand/or resonant circuits) can be configured to emit and/or further emitoscillating RF signals (or other forms of electromagnetic radiation,depending on the overall configuration). As a vehicle tire experienceswear resultant from usage (such as on or off-road driving), tire treadlayers in contact with pavement or ground (earth) may experiencedeformation, either instantaneously or over time (such as that observedfrom being “squished”, referring to at least partial flattening ofsections of the exposed vehicle tire tread layers during rotation orrolling, and/or from lateral motion as experienced during turning,etc.), therefore resultant signal frequency-shift and/or attenuationbehavior may change pursuant to such “squishing” as associated signalscan oscillate over one or more known amplitude ranges. In addition, orin the alternative, as the tire undergoes deformation, observed signalscan oscillate within a known frequency range corresponding to aparticular resonator, allowing for precise and accurate identificationof the type of deterioration occurring while it is occurring, ratherthan requiring the driver, passengers, and/or other vehicle occupants toexist the vehicle, while it is stationary, to observe tire treadconditions. Such a frequency-shifting oscillation is observable as afrequency shift back and forth between two or more frequencies withinthe known frequency range.

A wireless-capable strain, such as a geometric measure of deformationrepresenting the relative displacement between particles in a materialbody that is caused by external constraints or loads, sensor positionedon sides of the inner liner can monitor tire condition for automobilesafety (such by detecting damaged tires). Additionally, tire deformationor strain monitoring can indirectly provide information related to thedegree of friction between tires and road surface, which can then beused for the optimization of automobile tire control systems. Such tireinformation can be wirelessly transmitted to a receiver (and/ortransceiver) positioned in the wheel hub based on a resonant sensor(such as an impedance spectroscopy, IS, sensor) platform.

FIG. 11 is a schematic diagram 1100 a related to a resonant serialnumber-based digital encoding system for determining wear of vehicletires through ply-print encoding. The resonant serial number-baseddigital encoding system may be incorporated and/or function with any ofthe presently disclosed systems, methods, and sensors. The resonantserial number-based digital encoding system offers digital encoding oftires through ply-print encoding and thus offers cradle-to-the-grave(referring to a full lifespan) of tracking of tires (and relatedperformance metrics) and a usage profile without requiring traditionalelectronic devices susceptible to routine wear-and-tear in the tires.

Resonant serial number digital encoding of tire through tire tread layerprinting may facilitate, in some implementations, cradle-to-grave tiretracking of tires and usage without necessarily requiring the presenceof electronics within the tires. For example, along with tire wearsensing accomplished through impedance spectroscopy, additionalresonators may be digitally encoded onto, for example, one or moreprinted patterns for serial numbers used for telemetry tracking. As aresult, so-equipped vehicles can track tread wear, miles driven (e.g.,in total), and tire age without requiring radio-frequency identification(RFID) technology.

Along with tire wear sensing thru Impedance Spectroscopy (IS) and/orElectrochemical Impedance Spectroscopy (EIS), additional resonators canbe digitally encoded onto a printed pattern to provide a recognizableserial number for telemetry-based tire performance tracking. By beingprinted onto the body ply and/or tread layer incrementally, tiresincorporating the discussed printed carbon-based resonators can beinnately serialized.

FIG. 12 shows schematic diagram 1200 for resonant serial number encodingin tires. The serial number “6E” is shown encoded in aspecially-prepared array of printed carbon resonators configured toresonate according to the ‘ping’ stimulus-response diagram 1212 allowingfor convenient and reliable identification of that particular body plyand/or tread layer of the so-equipped vehicle tire.

FIG. 13 is presented to illustrate use of split ring resonators (SRRs)as resonance devices that contribute to the ensemble phenomenon arisingfrom different proximally-present resonator types. The figure shows theinner surface 1301 of a tire, where the inner surface has two split ringresonators (e.g., split ring resonator 1303A and split ring resonator1303B), each of which split ring resonator forms a circuit configuration1902 that can be tuned to attenuate a signal at a particular frequencyand/or to attenuate within a particular range of frequencies. In thisembodiment, circuit configuration 1902 is shown as a geometric patternthat corresponds to a substantially-circular split ring resonator;however, alternative circuit configurations can have different geometricpatterns (e.g., cylinders, ellipses, rectangles, ovals, squares, etc.),and as such, any conceivable geometric configuration is possible.Variations of the geometric configurations can be selected based on theimpact on resonation capabilities of the geometric pattern. Inparticular, and as shown, the geometric pattern can compriseself-assembled carbon-based particles having various agglomerationpatterns (e.g., agglomeration pattern 1306, agglomeration pattern 1308,and agglomeration pattern 1310), any one or more of which can constitutea concentrated region 1304 that can impact the resonation performance ofmaterials within which carbon-based microstructures are incorporated. Anagglomeration pattern and/or a series of agglomeration patterns may alsoimpact the resonation performance of materials within which carbon-basedmicrostructures are incorporated.

In various configurations the carbon-based microstructures are formed,at least in part by graphene. In this context, graphene refers to anallotrope of carbon in the form of a single layer of atoms in atwo-dimensional hexagonal lattice in which one atom forms each vertex.Co-location and/or juxtaposition of multiple of such hexagonal latticesinto more complex structures introduces further resonance effects. Forexample, juxtaposition 1302 of two sheets or platelets of graphene mayresonate between themselves at a frequency that is dependent on thelength, width, spacing, thickness, shape of the spacing, and/or otherphysical characteristics of the sheets or platelets and/or theirrelative juxtaposition to each other.

Table 1 depicts one possible chord of attenuations arising from theensemble effect. As shown in the table, each of the structures has adifferent resonant frequency domain that corresponds to its scaledesignation.

TABLE 1 Ensemble effect examples Structure Scale Designation ResonantFrequency Domain Printed Pattern Macro-scale Lower GHz (e.g., split ringresonator geometry) Agglomeration Meso-scale Higher GHz patternJuxtaposition Micro-scale Very high GHz of graphene sheets or plateletsMolecule Nano-scale THz

Any number of different split ring resonators can be printed onto asurface of a tire. Moreover, any number of different sizes of split ringresonators can be printed onto any of the surfaces of a tire. The choiceof materials and/or the size and/or other structural or dimensionalcharacteristics of a particular split ring resonator can be used tocontrol the resonation frequency of that particular resonator splitring. A series of differently-sized split ring resonators can be printedsuch that the pattern corresponds to a digitally encoded value.Stimulating the series of differently-sized split ring resonators withvia electromagnetic signal communication, for example, sweeping througha range from 8 GHz to 9 GHz or similar, and measuring the attenuationresponse through a range of the return leads to a recognizable encodedserial number. Many different encoding schemes are possible, and assuch, the non-limiting example of Table 2 is merely for illustration.

TABLE 2 Example encoding scheme Size (outer diameter) 1 mm 2 mm 2.5 mm 3mm 4 mm 5 mm 6 mm 7 mm Bit Assignment 8 7 6 5 4 3 2 1 Calibrated 8.890   8.690    8.655 8.570    8.470    8.380    8.350 8.275 AttenuationPoint (GHz) Encoded 6E Present Present Present Present Present SRRpattern Encoded 6E bit 0 1 1 0 1 1 1 0 pattern Encoded 4E PresentPresent Present Present SRR pattern Encoded 4E bit 0 1 0 0 1 1 1 0pattern Encoded E1 Present Present Present Present SRR pattern EncodedE1 bit 1 1 1 0 0 0 0 1 pattern

FIG. 14 shows a schematic diagram of a tire sensor 1400, according tosome implementations. In one implementation, the tire sensor 1400 mayinclude a section 1402 of a tire body (e.g., as shown in FIG. 9 ) withmultiple tire plies. The tire sensor 1400 may detect a temperature of atire ply 1408, e.g., in which the tire sensor 1400 is incorporated. Inone implementation, the tire sensor may include a ceramic material 1404(e.g., organized as a matrix), and one or more SRRs 1406, such as shownin FIG. 8 and elsewhere in the present disclosure). Each of the one ormore SRRs 1406 may have a natural resonance frequency (e.g., as shown inFIG. 16 ) that may shift in response to one or more of a change in anelastomeric property or a change in the temperature of the respectivetire. An electrically-conductive layer 1410 may be dielectricallyseparated from a respective SRR of the one or more SRRs 1406. In someimplementations, the tire sensor 1400 may be produced and shippedwithout being incorporated in a tire, such that later incorporationwithin a tire and/or tire ply is possible.

In addition, or the alternative, the tire sensor 1400 may beincorporated into a system (not shown in FIG. 14 ) configured to detecttire strain (e.g., as shown in FIG. 16 ) in a vehicle. The system mayinclude an antennae (e.g., as discussed in the present disclosurerelating to emission and/or propagation of electromagnetic signals)disposed on one or more of the vehicle or a vehicle component. Theantennae and configured to output an electromagnetic ping. The systemmay also include a tire including a body (e.g., as shown in FIG. 9 )formed of one or more tire plies. Any one or more of the tire plies mayinclude split-ring resonators (SRRs), e.g., as discussed in the presentdisclosure. In one implementation, each SRR has a natural resonancefrequency configured to proportionately shift (e.g., as shown in FIG. 16) in response to a change in an elastomeric property of a respective oneor more tire plies, e.g., reversible deformation, stress, and/or strain.

In some implementations, the described system may function to detectchanges in physical properties of materials outside of configurationsrelating to tires and/or vehicles, e.g., automobiles and trucks. Forexample, the system may detect changes in surface temperature of anairplane wing and/or other type of airfoil, e.g., associated withspacecraft and/or the like. Also, the system may permit for instanceswhere the one or more SRRs 1406 may be removably adhered onto patientsin a hospital setting, such that body temperature readings of therespective patient may be obtained without the usage of conventionalthermal sensors (e.g., relying on radiative heat transfer technology,etc.). In any of these examples, as well as others, such a system maydetect a physical property associated with a surface.

In one implementation, the system may include a single antennaeconfigured to output an electromagnetic ping and one or more flexiblesubstrates. Each of the flexible substrates may include a first sideincluding a plurality of split-ring resonators (SRRs) (e.g., such as theone or more SRRs 1406) disposed on the flexible substrate. Each SRR mayhave a natural resonance frequency that may proportionately shift (e.g.,as shown in FIG. 16 ) in response to a change in an elastomeric propertyof a respective one or more tire plies. The elastomeric property mayinclude one or more of a reversible deformation, stress, strain, ortemperature. In this way, the system may generate an absorption profile(e.g., referring to unique changes in absorption phenomena of theelectromagnetic ping output by the antennae). The system may include asecond side positioned opposite to the first side. The second side mayattach to the surface. The single antenna may analyze data associatedwith the absorption profile and output a topography of the physicalproperty.

FIG. 15 depicts a graph 1500 of measured resonant signature signalintensity (in decibels, dB) against height (in millimeters, mm) of tiretread layer loss, according to some implementations. As shown here,carbon-containing microstructures and/or microstructural materials canbe incorporated into sensors or, in some configurations, entire layersof one or more tire treads at a given concentration level, or multipledissimilar concentration levels (in each of the one or more tire treadlayers) to achieve the unique deterioration profile shown. That is, themeasure resonance signature (referring to the identifying “signature” ofa particular tire tread layer in question) can be ‘pinged’, as sodescribed herein, by one or more RF signals to demonstrate theattenuation of that emitted signal as shown.

A new tire tread layer can be configured to indicate a signal intensity(measured in decibels, dB) of approximately 0. That intensity can changeproportionate to the extent of deterioration of that tire tread layer.For instance, a 2 mm height loss of a tire tread layer, presumedly thetire tread layer in contact with pavement, can correspond with themeasure resonant signature signal intensity profile shown. A ‘ping’signal at 6.7 GHz can be measured at an intensity level of about 9 dB,or so, and so and so forth.

Accordingly, unique concentration levels, chemistries, dispersions,distributions and/or the like of the carbon-containing microstructurescan be embedded (or, in some cases, placed on one or more surfaces of)tire tread layers to achieve a unique and readily identifiable measuredresonant signature signal intensity as shown. A user of such a systemcan therefore immediately be notified to the exact extent and locationof tire tread wear as it occurs during driving, rather than beingrestricted to observe the tires while the vehicle is in a stationarycondition, a process that can be both time-consuming and cumbersome.

FIG. 16 depicts a graph 1600 of measured resonant signature signalintensity (in decibels, dB) against the natural resonance frequency ofsplit-ring resonator(s) (SRRs) incorporated into tire treads and/or tireplies (e.g., as discussed in the present disclosure), according to someimplementations. As shown here, carbon-containing and/or carbonaceousmicrostructures and/or microstructural materials can be incorporatedinto sensors or, in some configurations, entire layers of one or moretire treads at a given concentration level, or multiple dissimilarconcentration levels (in each of the one or more tire tread layers) toachieve the unique deterioration profile shown. That is, the measureresonance signature (referring to the identifying “signature” of aparticular tire tread layer in question) can be ‘pinged’, as sodescribed herein, by one or more RF signals to demonstrate the shift ofthat emitted signal as shown, e.g., representative and/or proportionateto an extent of reversible tire deformation, e.g., stress and/or strain(as may be encountered in drifting scenarios). In this way, SRR“response” signal behavior can be modeled as a function of tiredeformation, e.g., strain (associated with drifting), allowing for acomplete picture of tire condition and performance when considered withthe graph of FIG. 13 (which may be indicative of tire wear encounteredin routine forward rolling operations, etc.). Real-world scenariosresulting in lateral tire stiction loss may include drifting and/orhydroplaning, e.g., implying phenomena that occurs when a layer of waterbuilds between the wheels of the vehicle and the road surface, leadingto a loss of traction that prevents the vehicle from responding tocontrol inputs. If hydroplaning occurs to all contact wheelssimultaneously, the vehicle becomes, in effect, an uncontrolled sled.Usage of the presently disclosed SRRs and/or resonators in combinationwith antennae and/or signal processing equipment may effectivelyeliminate the need to rely on conventional hydroplaning detectiontechniques, e.g., through usage of a vibration detection unit coupledwith surfaces of a tire which may deteriorate and become compromisedthrough extended usage. In addition, FIG. 16 shows spectral response (insignal decibels) associated with lateral tire movement encounteredduring striction loss while drifting. In real-world scenarios, such astemporary stiction loss may be audibly heard through a high-pitched“screech,” as opposed to other sounds heard during rapid forwardrotation only. This type of periodic stiction loss (prior to thedrifting vehicle regaining stiction and/or traction) may be exhibited(not shown in FIG. 16 ) as a periodic and/or cyclical shift in thenatural resonance frequency of corresponding SRRs. Referring back toFIG. 16 , “screech” type circumstances may be visually depicted by minorperiodic and/or cyclical shifts in frequency of the various troughsand/or peaks of the curves.

As can be seen the real-time multi-modality resonator supports methodsfor measuring stiction using resonant materials-containing sensors forelastomer property change detection. In one setting, one or moreresonant materials-containing sensors for elastomer property changedetection are disposed in a location proximal to a transducer. Astimulation signal is emitted so as to excite the one or more resonantmaterials-containing sensors for elastomer property change detection.The emissions comprise electromagnetic energy that spans a knownfrequency range. A calibration signal is captured under a known stictioncondition. After receiving return signals that comprise, at least inpart, frequencies that are responsive to the stimulation signal, varioussignal processing techniques are applied to the return signal. Forexample, various signal processing techniques are applied to the returnsignal to compare with respect to the stimulation signal. Whereverfrequencies and/or amplitude of the return signal differs from thecalibration signal, a corresponding interfacial indirect permittivity(e.g., at the interface between a tire and the driving surface) iscalculated. Absolute and/or relative values of the interfacial indirectpermittivity are correlated to a stictional value (e.g., using acalibration table). Changes in the stictional value over time are inturn correlated to road and/or tire conditions.

The static and/or dynamic values that make up the aforementionedcalibration signal and/or calibration table can be based at least inpart on analysis of the stimulation signal, and/or analysis of anenvironment proximal to the transducer. Moreover, the aforementionedcalibration signal and/or calibration table can encompass permittivitycalibration signals, permeability calibration signals, temperaturecalibration signals, vibration calibration signals, doping calibrationsignals, etc. In one implementation, calibration procedures may beperformed under known and/or controlled environmental conditions, e.g.,dry pavement and in clear weather, to generate baseline data at variousforward-facing angular velocities (such that the test vehicle is onlymoving directly forward with no lateral skidding and/or slidingmovement). This baseline data then serves as one or more calibrationcurves from which deformation values may be subsequently compared and/orcalculated. In this way, clear performance changes may be observedrelative to the initial unstretched (baseline) calibration curve, e.g.,as shown in FIG. 16 .

Whenever and wherever the return signal differs from the calibrationsignal further analysis of the return signal with respect to thestimulation signal can serve to identify which of the frequencies of thereturn signal are different than the calibration signal. The differencescan be observed/measured as an attenuation of a frequency or frequencieswith respect to the calibration signal. Additionally, or alternatively,the differences can be observed/measured as a frequency shift (as shownin FIG. 16 relative to data corresponding stretched at 0.5%, etc.) ofpeaks with respect to peaks of the calibration signal.

FIG. 17 shows use of split ring resonant structures that are configuredto resonate in a manner that corresponds to an encoded serial number.Such a pattern of split ring resonant structures can be printed on tiresor other elastomers. As shown, the encoded serial number “μl” is shownby the presence of split ring resonators of four different sizes. Thestimulus-response diagram 1700 shows EM stimulus in a range of about 8GHz to about 9 GHz, whereas the response is shown as attenuation in arange from about −8 dB to about −18 dB. Stimulating the series ofdifferent sized split ring resonators with via electromagnetic signalcommunication across the range and measuring the S-parameters of thereturn across the range, leads to convenient and reliable identificationof that particular printed pattern. It follows then that, if a uniquepattern is printed onto each one of a run of tires, and if the patternis associated with an encoded serial number, then a determination of thespecific tire can be made based on the pattern's response to the EMinterrogation.

More specifically, if a unique pattern is printed onto each one of a runof tires, and if the pattern is associated with an encoded serialnumber, then a determination of the specific tire can be made based onmeasured S-parameters (e.g., S-parameter ratios that correspond toattenuation) in response to EM interrogation over an EM stimulus in arange corresponding to the encoding scheme. In the example of FIG. 17 ,the attenuations fall in a range from about −8 dB to about −18 dBhowever, in other measurements the attenuations fall in a range of about−1 dB to about −9 dB. In other measurements the attenuations fall in arange of about −10 dB to about −19 dB. In other measurements theattenuations fall in a range of about −20 dB to about −35 dB. Inempirical experimentation, the attenuations are substantiallyindependent of the number of differently-configured resonators that areproximally collocated on a tire surface. More particularly, in someexperimentation, the attenuations are particularly pronounced when theresonators are proximally collocated on a tire surface that is on thetread-side of a steel belt (e.g., in a steel belted radial tire).

The foregoing encoding and printing techniques can be used in tires andother elastomer-containing components. In some cases, printing theresonators is carried out at relatively high temperatures and/or withchemical agents (e.g., catalysts) such that chemical bonds are formedbetween the carbon atoms of the resonators and the elastomers. Thechemical bonds that are formed between the carbon atoms of theresonators and the elastomers contribute to ensemble effect, and assuch, calibration curves may be taken to account for the type and extentof the aforementioned chemical bonds.

The elastomer can contain any one or more types of rubber. Isoprene forexample is a common rubber formulation. Isoprene has its own single C—Cbonds and double bonds between the other molecular elements in theligands. Additional double carbon bonds formed by the high-temperatureprinting of the split ring resonators has the effect of increasedconductivity, which effect can be exploited to form larger, lowerfrequency resonators. Additionally, or alternatively, agglomerations canbe tuned into specific sizes, which would give rise to overtones thatcontribute to the ensemble effect, which in turn results in very highsensitivity given EM interrogation in a tuned range. In some cases, theresponse of the materials to EM interrogation is sufficientlydiscernable such that the age or other aspect of the elastomer's healthcan be determined (e.g., by comparison to one or more calibrationcurves).

More specifically, as elastomers age, the molecular spacing changes andcoupling and/or percolation of energy decreases correspondingly, thusshifting the response frequencies as the conductive localities becomemore and more isolated with respect to adjacent localities. In somecases, attenuation and/or return signal strength will change at specificfrequencies. Such changes can be determined over time, and the changescan be used to construct calibration curves.

The design of tires supports many possible locations for printing of thesplit ring resonators. As examples, split ring resonators can be locatedon any inner surface of a tire, including but not limited to the capply, and/or on or near the steel belts (e.g., on the tread side of asteel belt), and/or on or near a radial ply, and/or on the sidewall,and/or on the bead chafers, and/or on the beads, etc.

Use of the split ring resonator techniques are not limited to onlytires. The techniques can be applied to any elastomer-containingcomponents such belts and hoses. Moreover, the use of the split ringresonator techniques are not limited to only vehicles. That is, sinceconsumables exist in organic powertrain and/or drive train components ina wide range of motive devices (e.g., in industrial mechanical systems),the split ring resonator techniques can be applied to those consumablesas well. Some aspects of wear phenomena are a consequence of friction,heat, heat cycling and corrosion, any of which can result in and/oraccelerate changes in the molecular structure of the materials. Changesin the molecular structure of the materials is detectable under EMinterrogation. More specifically, by calculating a frequency shift, aparticular sample's response (e.g., an aged sample's response) under aparticular EM interrogation regime with respect to a calibration curve,the age or health of the material can be assessed based on the magnitudeof the frequency shift.

FIG. 18A through FIG. 18Y depict carbon-based materials, growths,agglomerates, aggregates, sheets, particles and/or the like, such asthose self-nucleated in-flight in a reaction chamber or reactor from acarbon-containing gaseous species such as methane (CH₄), for example, asdisclosed in commonly owned U.S. Pat. No. 11,198,611, which isincorporated herein by reference in its entirety.

The shown carbon-based nanoparticles and aggregates can be characterizedby a high degree of “uniformity” (such as a high mass fraction ofdesired carbon allotropes), a high degree of “order” (such as a lowconcentration of defects), and/or a high degree of “purity” (such as alow concentration of elemental impurities), in contrast to the loweruniformity, less ordered, and lower purity particles achievable withconventional systems and methods.

The nanoparticles produced using the methods described herein cancontain multi-walled spherical fullerenes (MWSFs) or connected MWSFs andhave a high uniformity (such as, a ratio of graphene to MWSF from 20% to80%), a high degree of order (such as, a Raman signature with anI_(D)/I_(G) ratio from 0.95 to 1.05), and a high degree of purity (suchas, the ratio of carbon to other elements (other than hydrogen) isgreater than 99.9%). The nanoparticles produced using the methodsdescribed herein contain MWSFs or connected MWSFs, and the MWSFs do notcontain a core composed of impurity elements other than carbon. Theparticles produced using the methods described herein can be aggregatescontaining the nanoparticles described above with large diameters (suchas greater than 10 μm).

Conventional methods have been used to produce particles containingmulti-walled spherical fullerenes with a high degree of order but canlead to end products with a variety of shortcomings. For example, hightemperature synthesis techniques lead to particles with a mixture ofmany carbon allotropes and therefore low uniformity (such as less than20% fullerenes relative to other carbon allotropes) and/or smallparticle sizes (such as less than 1 μm, or less than 100 nm in somecases). Methods using catalysts can lead to products that include thecatalyst elements and therefore have relatively lower purity (referringto less than 95% carbon to other elements) as well. These undesirableproperties also often lead to undesirable electrical properties of theresulting carbon particles (such as, electrical conductivity of lessthan 1,000 S/m).

The carbon nanoparticles and aggregates described herein can becharacterized by Raman spectroscopy that is indicative of the highdegree of order and uniformity of structure. The uniform ordered and/orpure carbon nanoparticles and aggregates described herein can beproduced using relatively high speed, low cost improved thermal reactorsand methods, as described below.

The term “graphene”, as both commonly understood and as referred toherein, implies an allotrope of carbon in the form of a two-dimensional,atomic-scale, hexagonal lattice in which one atom forms each vertex. Thecarbon atoms in graphene are sp²-bonded. Additionally, graphene has aRaman spectrum with two main peaks: a G-mode at approximately 1580 cm⁻¹and a D-mode at approximately 1350 cm⁻¹ (when using a 532 nm excitationlaser).

The term “fullerene”, as both commonly understood and as referred toherein, implies a molecule of carbon in the form of a hollow sphere,ellipsoid, tube, or other shapes. Spherical fullerenes can also bereferred to as Buckminsterfullerenes, or buckyballs. Cylindricalfullerenes can also be referred to as carbon nanotubes. Fullerenes aresimilar in structure to graphite, which is composed of stacked graphenesheets of linked hexagonal rings. Fullerenes may also contain pentagonal(or sometimes heptagonal) rings.

The term “multi-walled fullerene”, as both commonly understood and asreferred to herein, implies fullerenes with multiple concentric layers.For example, multi-walled nanotubes (MWNTs) contain multiple rolledlayers (concentric tubes) of graphene. Multi-walled spherical fullerenes(MWSFs) contain multiple concentric spheres of fullerenes.

The term “nanoparticle”, as both commonly understood and as referred toherein, implies a particle that measures from 1 nm to 989 nm. Thenanoparticle can include one or more structural characteristics (suchas, crystal structure, defect concentration, etc.), and one or moretypes of atoms. The nanoparticle can be any shape, including but notlimited to spherical shapes, spheroidal shapes, dumbbell shapes,cylindrical shapes, elongated cylindrical type shapes, rectangularand/or prism shapes, disk shapes, wire shapes, irregular shapes, denseshapes (such as, with few voids), porous shapes (such as, with manyvoids), etc.

The term “aggregate”, as both commonly understood and as referred toherein, implies a plurality of nanoparticles that are connected togetherby Van der Waals forces, by covalent bonds, by ionic bonds, by metallicbonds, or by other physical or chemical interactions. Aggregates canvary in size considerably, but in general are larger than about 500 nm.

A carbon nanoparticle can include two (2) or more connected multi-walledspherical fullerenes (MWSFs) and layers of graphene coating theconnected MWSFs and can be formed to be independent of a core composedof impurity elements other than carbon. A carbon nanoparticle, asdescribed herein, can include two (2) or more connected multi-walledspherical fullerenes (MWSFs) and layers of graphene coating theconnected MWSFs. In such a configuration, where the MWSFs do not containa void (referring to a space with no carbon atoms greater thanapproximately 0.5 nm or greater than approximately 1 nm) at the center.The connected MWSFs can be formed of concentric, well-ordered spheres ofsp²-hybridized carbon atoms (which is in favorable contrast toconventional spheres of haphazardly-ordered, non-uniform, amorphouscarbon particles, which can otherwise fail to achieve any one or more ofthe unexpected and favorable properties disclosed herein).

The nanoparticles containing the connected MWSFs have an averagediameter in a range from 5 to 500 nm, or from 5 to 250 nm, or from 5 to100 nm, or from 5 to 50 nm, or from 10 to 500 nm, or from 10 to 250 nm,or from 10 to 100 nm, or from 10 to 50 nm, or from 40 to 500 nm, or from40 to 250 nm, or from 40 to 100 nm, or from 50 to 500 nm, or from 50 to250 nm, or from 50 to 100 nm.

The carbon nanoparticles described herein form aggregates, wherein manynanoparticles aggregate together to form a larger unit. A carbonaggregate can a plurality of carbon nanoparticles. A diameter across thecarbon aggregate can be a range from 10 to 500 μm, or from 50 to 500 μm,or from 100 to 500 μm, or from 250 to 500 μm, or from 10 to 250 μm, orfrom 10 to 100 μm, or from 10 to 50 μm. The aggregate can be formed froma plurality of carbon nanoparticles, as defined above. Aggregates cancontain connected MWSFs, such as those with a high uniformity metric(such as a ratio of graphene to MWSF from 20% to 80%), a high degree oforder (such as a Raman signature with an I_(D)/I_(G) ratio from 0.95 to1.05), and a high degree of purity (such as greater than 99.9% carbon).

Aggregates of carbon nanoparticles, referring primarily to those withdiameters in the ranges described above, especially particles greaterthan 10 μm, are generally easier to collect than particles or aggregatesof particles that are smaller than 500 nm. The ease of collectionreduces the cost of manufacturing equipment used in the production ofthe carbon nanoparticles and increases the yield of the carbonnanoparticles. Particles greater than 10 μm in size also pose fewersafety concerns compared to the risks of handling smaller nanoparticles,such as, potential health and safety risks due to inhalation of thesmaller nanoparticles. The lower health and safety risks, thus, furtherreduce the manufacturing cost.

A carbon nanoparticle, in reference to that disclosed herein, can have aratio of graphene to MWSFs from 10% to 90%, or from 10% to 80%, or from10% to 60%, or from 10% to 40%, or from 10% to 20%, or from 20% to 40%,or from 20% to 90%, or from 40% to 90%, or from 60% to 90%, or from 80%to 90%. A carbon aggregate has a ratio of graphene to MWSFs is from 10%to 90%, or from 10% to 80%, or from 10% to 60%, or from 10% to 40%, orfrom 10% to 20%, or from 20% to 40%, or from 20% to 90%, or from 40% to90%, or from 60% to 90%, or from 80% to 90%. A carbon nanoparticle has aratio of graphene to connected MWSFs from 10% to 90%, or from 10% to80%, or from 10% to 60%, or from 10% to 40%, or from 10% to 20%, or from20% to 40%, or from 20% to 90%, or from 40% to 90%, or from 60% to 90%,or from 80% to 90%. A carbon aggregate has a ratio of graphene toconnected MWSFs is from 10% to 90%, or from 10% to 80%, or from 10% to60%, or from 10% to 40%, or from 10% to 20%, or from 20% to 40%, or from20% to 90%, or from 40% to 90%, or from 60% to 90%, or from 80% to 90%.

Raman spectroscopy can be used to characterize carbon allotropes todistinguish their molecular structures. For example, graphene can becharacterized using Raman spectroscopy to determine information such asorder/disorder, edge and grain boundaries, thickness, number of layers,doping, strain, and thermal conductivity. MWSFs have also beencharacterized using Raman spectroscopy to determine the degree of orderof the MWSFs.

Raman spectroscopy is used to characterize the structure of MWSFs orconnected MWSFs used in reference to that incorporated within thevarious tire-related plies of tires as discussed herein. The main peaksin the Raman spectra are the G-mode and the D-mode. The G-mode isattributed to the vibration of carbon atoms in sp²-hybridized carbonnetworks, and the D-mode is related to the breathing of hexagonal carbonrings with defects. In some circumstances, defects may be present, yetmay not be detectable in the Raman spectra. For example, if thepresented crystalline structure is orthogonal with respect to the basalplane, the D-peak will show an increase. Alternatively, if presentedwith a perfectly planar surface that is parallel with respect to thebasal plane, the D-peak will be zero.

When using 532 nm incident light, the Raman G-mode is typically at 1582cm⁻¹ for planar graphite, however, can be downshifted for MWSFs orconnected MWSFs (such as, down to 1565 cm¹ or down to 1580 cm¹). TheD-mode is observed at approximately 1350 cm¹ in the Raman spectra ofMWSFs or connected MWSFs. The ratio of the intensities of the D-modepeak to G-mode peak (such as, the I_(D)/I_(G)) is related to the degreeof order of the MWSFs, where a lower I_(D)/I_(G) indicates a higherdegree of order. An I_(D)/I_(G) near or below 1 indicates a relativelyhigh degree of order, and an I_(D)/I_(G) greater than 1.1 indicates alower degree of order.

A carbon nanoparticle or a carbon aggregate containing MWSFs orconnected MWSFs, as described herein, can have and/or demonstrate aRaman spectrum with a first Raman peak at about 1350 cm⁻¹ and a secondRaman peak at about 1580 cm⁻¹ when using 532 nm incident light. Theratio of an intensity of the first Raman peak to an intensity of thesecond Raman peak (such as, the I_(D)/I_(G)) for the nanoparticles orthe aggregates described herein can be in a range from 0.95 to 1.05, orfrom 0.9 to 1.1, or from 0.8 to 1.2, or from 0.9 to 1.2, or from 0.8 to1.1, or from 0.5 to 1.5, or less than 1.5, or less than 1.2, or lessthan 1.1, or less than 1, or less than 0.95, or less than 0.9, or lessthan 0.8.

A carbon aggregate containing MWSFs or connected MWSFs, as definedabove, has a high purity. The carbon aggregate containing MWSFs orconnected MWSFs has a ratio of carbon to metals of greater than 99.99%,or greater than 99.95%, or greater than 99.9%, or greater than 99.8%, orgreater than 99.5%, or greater than 99%. The carbon aggregate has aratio of carbon to other elements of greater than 99.99%, or greaterthan 99.95%, or greater than 99.9%, or greater than 99.5%, or greaterthan 99%, or greater than 90%, or greater than 80%, or greater than 70%,or greater than 60%. The carbon aggregate has a ratio of carbon to otherelements (except for hydrogen) of greater than 99.99%, or greater than99.95%, or greater than 99.9%, or greater than 99.8%, or greater than99.5%, or greater than 99%, or greater than 90%, or greater than 80%, orgreater than 70%, or greater than 60%.

A carbon aggregate containing MWSFs or connected MWSFs, as definedabove, has a high specific surface area. The carbon aggregate has aBrunauer, Emmett and Teller (BET) specific surface area from 10 to 200m²/g, or from 10 to 100 m²/g, or from 10 to 50 m²/g, or from 50 to 200m²/g, or from 50 to 100 m²/g, or from 10 to 1000 m²/g.

A carbon aggregate containing MWSFs or connected MWSFs, as definedabove, has a high electrical conductivity. A carbon aggregate containingMWSFs or connected MWSFs, as defined above, is compressed into a pelletand the pellet has an electrical conductivity greater than 500 S/m, orgreater than 1,000 S/m, or greater than 2,000 S/m, or greater than 3,000S/m, or greater than 4,000 S/m, or greater than 5,000 S/m, or greaterthan 10,000 S/m, or greater than 20,000 S/m, or greater than 30,000 S/m,or greater than 40,000 S/m, or greater than 50,000 S/m, or greater than60,000 S/m, or greater than 70,000 S/m, or from 500 S/m to 100,000 S/m,or from 500 S/m to 1,000 S/m, or from 500 S/m to 10,000 S/m, or from 500S/m to 20,000 S/m, or from 500 S/m to 100,000 S/m, or from 1000 S/m to10,000 S/m, or from 1,000 S/m to 20,000 S/m, or from 10,000 to 100,000S/m, or from 10,000 S/m to 80,000 S/m, or from 500 S/m to 10,000 S/m. Insome cases, the density of the pellet is approximately 1 g/cm³, orapproximately 1.2 g/cm³, or approximately 1.5 g/cm³, or approximately 2g/cm³, or approximately 2.2 g/cm³, or approximately 2.5 g/cm³, orapproximately 3 g/cm³. Additionally, tests have been performed in whichcompressed pellets of the carbon aggregate materials have been formedwith compressions of 2,000 psi and 12,000 psi and with annealingtemperatures of 800° C. and 1,000° C. The higher compression and/or thehigher annealing temperatures generally result in pellets with a higherdegree of electrical conductivity, including in the range of 12,410.0S/m to 13,173.3 S/m.

The carbon nanoparticles and aggregates described herein can be producedusing thermal reactors and methods. Further details pertaining tothermal reactors and/or methods of use can be found in U.S. Pat. No.9,862,602, issued Jan. 9, 2018, entitled “CRACKING OF A PROCESS GAS”,which is hereby incorporated by reference in its entirety. Additionally,carbon-containing and/or hydrocarbon precursors (referring to at leastmethane, ethane, propane, butane, and natural gas) can be used with thethermal reactors to produce the carbon nanoparticles and the carbonaggregates described herein.

The carbon nanoparticles and aggregates described herein are producedusing the thermal reactors with gas flow rates from 1 slm to 10 slm, orfrom 0.1 slm to 20 slm, or from 1 slm to 5 slm, or from 5 slm to 10 slm,or greater than 1 slm, or greater than 5 slm. The carbon nanoparticlesand aggregates described herein are produced using the thermal reactorswith gas resonance times from 0.1 seconds (s) to 30 s, or from 0.1 s to10 s, or from 1 s to 10 s, or from 1 s to 5 s, from 5 s to 10 s, orgreater than 0.1 seconds, or greater than 1 s, or greater than 5 s, orless than 30 s.

The carbon nanoparticles and aggregates described herein can be producedusing the thermal reactors with production rates from 10 g/hr to 200g/hr, or from 30 g/hr to 200 g/hr, or from 30 g/hr to 100 g/hr, or from30 g/hr to 60 g/hr, or from 10 g/hr to 100 g/hr, or greater than 10g/hr, or greater than 30 g/hr, or greater than 100 g/hr.

Thermal reactors (or other cracking apparatuses) and thermal reactormethods (or other cracking methods) can be used for refining,pyrolizing, dissociating or cracking feedstock process gases into itsconstituents to produce the carbon nanoparticles and the carbonaggregates described herein, as well as other solid and/or gaseousproducts (such as, hydrogen gas and/or lower order hydrocarbon gases).The feedstock process gases generally include, for example, hydrogen gas(H²), carbon dioxide (CO²), C¹ to C¹⁰ hydrocarbons, aromatichydrocarbons, and/or other hydrocarbon gases such as natural gas,methane, ethane, propane, butane, isobutane, saturated/unsaturatedhydrocarbon gases, ethene, propene, etc., and mixtures thereof. Thecarbon nanoparticles and the carbon aggregates can include, for example,multi-walled spherical fullerenes (MWSFs), connected MWSFs, carbonnanospheres, graphene, graphite, highly ordered pyrolytic graphite,single-walled nanotubes, multi-walled nanotubes, other solid carbonproducts, and/or the carbon nanoparticles and the carbon aggregatesdescribed herein.

Methods for producing the carbon nanoparticles and the carbon aggregatesdescribed herein can include thermal cracking methods that use, forexample, an elongated longitudinal heating element optionally enclosedwithin an elongated casing, housing, or body of a thermal crackingapparatus. The body can include, for example, one or more tubes or otherappropriate enclosures made of stainless steel, titanium, graphite,quartz, or the like. The body of the thermal cracking apparatus isgenerally cylindrical in shape with a central elongate longitudinal axisarranged vertically and a feedstock process gas inlet at or near a topof the body. The feedstock process gas can flow longitudinally downthrough the body or a portion thereof. In the vertical configuration,both gas flow and gravity assist in the removal of the solid productsfrom the body of the thermal cracking apparatus.

The heating element can include any one or more of a heating lamp, oneor more resistive wires or filaments (or twisted wires), metalfilaments, metallic strips, or rods, and/or other appropriate thermalradical generators or elements that can be heated to a specifictemperature (such a, a molecular cracking temperature) sufficient tothermally crack molecules of the feedstock process gas. The heatingelement can be disposed, located, or arranged to extend centrally withinthe body of the thermal cracking apparatus along the centrallongitudinal axis thereof. In configurations having only one heatingelement can include it placed at or concentric with the centrallongitudinal axis; alternatively, for configurations having multipleheating elements can include them spaced or offset generallysymmetrically or concentrically at locations near and around andparallel to the central longitudinal axis.

Thermal cracking to produce the carbon nanoparticles and aggregatesdescribed herein can be achieved by flowing the feedstock process gasover, or in contact with, or within the vicinity of, the heating elementwithin a longitudinal elongated reaction zone generated by heat from theheating element and defined by and contained inside the body of thethermal cracking apparatus to heat the feedstock process gas to or at aspecific molecular cracking temperature.

The reaction zone can be considered to be the region surrounding theheating element and close enough to the heating element for thefeedstock process gas to receive sufficient heat to thermally crack themolecules thereof. The reaction zone is thus generally axially alignedor concentric with the central longitudinal axis of the body. Thethermal cracking is performed under a specific pressure. The feedstockprocess gas is circulated around or across the outside surface of acontainer of the reaction zone or a heating chamber to cool thecontainer or chamber and preheat the feedstock process gas beforeflowing the feedstock process gas into the reaction zone.

The carbon nanoparticles and aggregates described herein and/or hydrogengas are produced without the use of catalysts. Accordingly, the processcan be entirely catalyst free.

Disclosed methods and systems can advantageously be rapidly scaled up orscaled down for different production levels as may be desired, such asbeing scalable to provide a standalone hydrogen and/or carbonnanoparticle producing station, a hydrocarbon source, or a fuel cellstation, to provide higher capacity systems, such as, for a refineryand/or the like.

A thermal cracking apparatus for cracking a feedstock process gas toproduce the carbon nanoparticles and aggregates described herein includea body, a feedstock process gas inlet, and an elongated heating element.The body has an inner volume with a longitudinal axis. The inner volumehas a reaction zone concentric with the longitudinal axis. A feedstockprocess gas can be flowed into the inner volume through the feedstockprocess gas inlet during thermal cracking operations. The elongatedheating element can be disposed within the inner volume along thelongitudinal axis and is surrounded by the reaction zone. During thethermal cracking operations, the elongated heating element is heated byelectrical power to a molecular cracking temperature to generate thereaction zone, the feedstock process gas is heated by heat from theelongated heating element, and the heat thermally cracks molecules ofthe feedstock process gas that are within the reaction zone intoconstituents of the molecules.

A method for cracking a feedstock process gas to produce the carbonnanoparticles and aggregates described herein can include at least anyone or more of the following: (1) providing a thermal cracking apparatushaving an inner volume that has a longitudinal axis and an elongatedheating element disposed within the inner volume along the longitudinalaxis; (2) heating the elongated heating element by electrical power to amolecular cracking temperature to generate a longitudinal elongatedreaction zone within the inner volume; (3) flowing a feedstock processgas into the inner volume and through the longitudinal elongatedreaction zone (such as, wherein the feedstock process gas is heated byheat from the elongated heating element); and (4) thermally crackingmolecules of the feedstock process gas within the longitudinal elongatedreaction zone into constituents thereof (such as, hydrogen gas and oneor more solid products) as the feedstock process gas flows through thelongitudinal elongated reaction zone.

The feedstock process gas used to produce the carbon nanoparticles andaggregates described herein can include a hydrocarbon gas. The resultsof cracking can, in turn, further include hydrogen in gaseous form (suchas, H²) and various forms of the carbon nanoparticles and aggregatesdescribed herein. The carbon nanoparticles and aggregates include two ormore MWSFs and layers of graphene coating the MWSFs, and/or connectedMWSFs and layers of graphene coating the connected MWSFs. The feedstockprocess gas is preheated (such as, to 100° C. to 500° C.) by flowing thefeedstock process gas through a gas preheating region between a heatingchamber and a shell of the thermal cracking apparatus before flowing thefeedstock process gas into the inner volume. A gas having nanoparticlestherein is flowed into the inner volume and through the longitudinalelongated reaction zone to mix with the feedstock process gas, to form acoating of a solid product (such as, layers of graphene) around thenanoparticles.

The carbon nanoparticles and aggregates containing multi-walledspherical fullerenes (MWSFs) or connected MWSFs described herein can beproduced and collected without requiring the completion of anypost-processing treatments or operations. Alternatively, somepost-processing can be performed on one or more of the presentlydisclosed MWSFs. Some examples of post-processing involved in making andusing resonant materials include mechanical processing such as ballmilling, grinding, attrition milling, micro fluidizing, and othertechniques to reduce the particle size without damaging the MWSFs. Somefurther examples of post-processing include exfoliation processes(referring to the complete separation of layers of carbon-containingmaterial, such as the creation or extraction of layers of graphene fromgraphite, etc.) including sheer mixing, chemical etching, oxidizing(such as the Hummer method), thermal annealing, doping by addingelements during annealing (such as sulfur and/or nitrogen), steaming,filtering, and lyophilization, among others. Some examples ofpost-processing include sintering processes such as spark plasmasintering (SPS), direct current sintering, microwave sintering, andultraviolet (UV) sintering, which can be conducted at high pressure andtemperature in an inert gas. Multiple post-processing methods can beused together or in a series. The post-processing producesfunctionalized carbon nanoparticles or aggregates containingmulti-walled spherical fullerenes (MWSFs) or connected MWSFs.

Materials can be mixed together in different combinations, quantitiesand/or ratios. Different carbon nanoparticles and aggregates containingMWSFs or connected MWSFs described herein can be mixed together prior toone or more post-processing operations, if any at all. For example,different carbon nanoparticles and aggregates containing MWSFs orconnected MWSFs with different properties (such as, different sizes,different compositions, different purities, from different processingruns, etc.) can be mixed together. The carbon nanoparticles andaggregates containing MWSFs or connected MWSFs described herein can bemixed with graphene to change the ratio of the connected MWSFs tographene in the mixture. Different carbon nanoparticles and aggregatescontaining MWSFs or connected MWSFs described herein can be mixedtogether after post-processing. Different carbon nanoparticles andaggregates containing MWSFs or connected MWSFs with different propertiesand/or different post-processing methods (such as, different sizes,different compositions, different functionality, different surfaceproperties, different surface areas) can be mixed together in anyquantity, ratio and/or combination.

The carbon nanoparticles and aggregates described herein are producedand collected, and subsequently processed by mechanical grinding,milling, and/or exfoliating. The processing (such as, by mechanicalgrinding, milling, exfoliating, etc.) can reduce the average size of theparticles. The processing (such as, by mechanical grinding, milling,exfoliating, etc.) increases the average surface area of the particles.The processing by mechanical grinding, milling and/or exfoliation shearsoff some fraction of the carbon layers, producing sheets of graphitemixed with the carbon nanoparticles.

The mechanical grinding or milling is performed using a ball mill, aplanetary mill, a rod mill, a shear mixer, a high-shear granulator, anautogenous mill, or other types of machining used to break solidmaterials into smaller pieces by grinding, crushing, or cutting. Themechanical grinding, milling and/or exfoliating is performed wet or dry.The mechanical grinding is performed by grinding for some period oftime, then idling for some period of time, and repeating the grindingand idling for a number of cycles. The grinding period is from 1 minute(min) to 20 mins, or from 1 min to 10 mins, or from 3 mins to 8 mins, orapproximately 3 mins, or approximately 8 mins. The idling period is from1 min to 10 mins, or approximately 5 mins, or approximately 6 mins. Thenumber of grinding and idling cycles is from 1 min to 100 mins, or from5 mins to 100 mins, or from 10 mins to 100 mins, or from 5 mins to 10mins, or from 5 mins to 20 mins. The total amount of time of grindingand idling is from 10 mins to 1,200 mins, or from 10 mins to 600 mins,or from 10 mins to 240 mins, or from 10 mins to 120 mins, or from 100mins to 90 mins, or from 10 mins to 60 mins, or approximately 90 mins,or approximately mins minutes.

The grinding steps in the cycle are performed by rotating a mill in onedirection for a first cycle (such as, clockwise), and then rotating amill in the opposite direction (such as, counterclockwise) for the nextcycle. The mechanical grinding or milling is performed using a ballmill, and the grinding steps are performed using a rotation speed from100 to 1000 rpm, or from 100 to 500 rpm, or approximately 400 rpm. Themechanical grinding or milling is performed using a ball mill that usesa milling media with a diameter from 0.1 mm to 20 mm, or from 0.1 mm to10 mm, or from 1 mm to 10 mm, or approximately 0.1 mm, or approximately1 mm, or approximately 10 mm. The mechanical grinding or milling isperformed using a ball mill that uses a milling media composed of metalsuch as steel, an oxide such as zirconium oxide (zirconia), yttriastabilized zirconium oxide, silica, alumina, magnesium oxide, or otherhard materials such as silicon carbide or tungsten carbide.

The carbon nanoparticles and aggregates described herein are producedand collected, and subsequently processed using elevated temperaturessuch as thermal annealing or sintering. The processing using elevatedtemperatures is done in an inert environment such as nitrogen or argon.The processing using elevated temperatures is done at atmosphericpressure, or under vacuum, or at low pressure. The processing usingelevated temperatures is done at a temperature from 500° C. to 2,500°C., or from 500° C. to 1,500° C., or from 800° C. to 1,500° C., or from800° C. to 1,200° C., or from 800° C. to 1,000° C., or from 2,000° C. to2,400° C., or approximately 8,00° C., or approximately 1,000° C., orapproximately 1,500° C., or approximately 2,000° C., or approximately2,400° C.

The carbon nanoparticles and aggregates described herein are producedand collected, and subsequently, in post processing operations,additional elements or compounds are added to the carbon nanoparticles,thereby incorporating the unique properties of the carbon nanoparticlesand aggregates into other mixtures of materials.

Either before or after post-processing, the carbon nanoparticles andaggregates described herein are added to solids, liquids or slurries ofother elements or compounds to form additional mixtures of materialsincorporating the unique properties of the carbon nanoparticles andaggregates. The carbon nanoparticles and aggregates described herein aremixed with other solid particles, polymers, or other materials.

Either before or after post-processing, the carbon nanoparticles andaggregates described herein are used in various applications beyondapplications pertaining to making and using resonant materials. Suchapplications including but not limited to transportation applications(such as, automobile and truck tires, couplings, mounts, elastomeric“o”-rings, hoses, sealants, grommets, etc.) and industrial applications(such as, rubber additives, functionalized additives for polymericmaterials, additives for epoxies, etc.).

FIGS. 18A and 18B show transmission electron microscope (TEM) images ofas-synthesized carbon nanoparticles. The carbon nanoparticles of FIG.18A (at a first magnification) and FIG. 18B (at a second magnification)contain connected multi-walled spherical fullerenes (MWSFs) withgraphene layers that coat the connected MWSFs. The ratio of MWSF tographene allotropes in this example is approximately 80% due to therelatively short resonance times. The MWSFs in FIG. 18B areapproximately 5 nm to 10 nm in diameter, and the diameter can be from 5nm to 500 nm using the conditions described above. The average diameteracross the MWSFs is in a range from 5 nm to 500 nm, or from 5 nm to 250nm, or from 5 nm to 100 nm, or from 5 nm to 50 nm, or from 10 nm to 500nm, or from 10 nm to 250 nm, or from 10 nm to 100 nm, or from 10 nm to50 nm, or from 40 nm to 500 nm, or from 40 nm to 250 nm, or from 40 nmto 100 nm, or from 50 nm to 500 nm, or from 50 nm to 250 nm, or from 50nm to 100 nm. No catalyst was used in this process, and therefore, thereis no central seed containing contaminants. The aggregate particlesproduced in this example had a particle size of approximately 10 μm to100 μm, or approximately 10 μm to 500 μm.

FIG. 18C shows the Raman spectrum of the as-synthesized aggregates inthis example taken with 532 nm incident light. The I_(D)/I_(G) for theaggregates produced in this example is from approximately 0.99 to 1.03,indicating that the aggregates were composed of carbon allotropes with ahigh degree of order.

FIG. 18D and FIG. 18E show example TEM images of the carbonnanoparticles after size reduction by grinding in a ball mill. The ballmilling was performed in cycles with a 3-minute (min) counter-clockwisegrinding operation, followed by a 6 min idle operation, followed by a3-min clockwise grinding operation, followed by a 6-min idle operation.The grinding operations were performed using a rotation speed of 400rpm. The milling media was zirconia and ranged in size from 0.1 mm to 10mm. The total size reduction processing time was from 60 mins to 120mins. After size reduction, the aggregate particles produced in thisexample had a particle size of approximately 1 μm to 5 μm. The carbonnanoparticles after size reduction are connected MWSFs with layers ofgraphene coating the connected MWSFs.

FIG. 18F shows a Raman spectrum from these aggregates after sizereduction taken with a 532 nm incident light. The I_(D)/I_(G) for theaggregate particles in this example after size reduction isapproximately 1.04. Additionally, the particles after size reduction hada Brunauer, Emmett and Teller (BET) specific surface area ofapproximately 40 m²/g to 50 m²/g.

The purity of the aggregates produced in this sample were measured usingmass spectrometry and x-ray fluorescence (XRF) spectroscopy. The ratioof carbon to other elements, except for hydrogen, measured in 16different batches was from 99.86% to 99.98%, with an average of 99.94%carbon.

In this example, carbon nanoparticles were generated using a thermalhot-wire processing system. The precursor material was methane, whichwas flowed from 1 slm to 5 slm. With these flow rates and the toolgeometry, the resonance time of the gas in the reaction chamber was fromapproximately 20 second to 30 seconds, and the carbon particleproduction rate was from approximately 20 g/hr.

Further details pertaining to such a processing system can be found inthe previously mentioned U.S. Pat. No. 9,862,602, titled “CRACKING OF APROCESS GAS.”

EXAMPLES Example 1

FIG. 18G (shown enlarged as FIG. 15 ), FIG. 18H (shown enlarged as FIG.16 ) and FIG. 18I (shown enlarged as FIG. 17 ) show TEM images ofas-synthesized carbon nanoparticles of this example. The carbonnanoparticles contain connected multi-walled spherical fullerenes(MWSFs) with layers of graphene coating the connected MWSFs. The ratioof multi-walled fullerenes to graphene allotropes in this example isapproximately 30% due to the relatively long resonance times allowingthicker, or more, layers of graphene to coat the MWSFs. No catalyst wasused in this process, and therefore, there is no central seed containingcontaminants. The as-synthesized aggregate particles produced in thisexample had particle sizes of approximately 10 μm to 500 μm. FIG. 18Jshows a Raman spectrum from the aggregates of this example. The Ramansignature of the as-synthesized particles in this example is indicativeof the thicker graphene layers which coat the MWSFs in theas-synthesized material. Additionally, the as-synthesized particles hada Brunauer, Emmett and Teller (BET) specific surface area ofapproximately 90 m²/g to 100 m²/g.

Example 2

FIG. 18K and FIG. 18L show TEM images of the carbon nanoparticles ofthis example. Specifically, the images depict the carbon nanoparticlesafter performance of size reduction by grinding in a ball mill. The sizereduction process conditions were the same as those described aspertains to the foregoing FIG. 18G through FIG. 18J. After sizereduction, the aggregate particles produced in this example had aparticle size of approximately 1 μm to 5 μm. The TEM images show thatthe connected MWSFs that were buried in the graphene coating can beobserved after size reduction. FIG. 18M shows a Raman spectrum from theaggregates of this example after size reduction taken with 532 nmincident light. The I_(D)/I_(G) for the aggregate particles in thisexample after size reduction is approximately 1, indicating that theconnected MWSFs that were buried in the graphene coating as-synthesizedhad become detectable in Raman after size reduction, and were wellordered. The particles after size reduction had a Brunauer, Emmett andTeller (BET) specific surface area of approximately 90 m²/g to 100 m²/g.

Example 3

FIG. 18N is a scanning electron microscope (SEM) image of carbonaggregates showing the graphite and graphene allotropes at a firstmagnification. FIG. 18O is a SEM image of carbon aggregates showing thegraphite and graphene allotropes at a second magnification. The layeredgraphene is clearly shown within the distortion (wrinkles) of thecarbon. The 3D structure of the carbon allotropes is also visible.

The particle size distribution of the carbon particles of FIG. 18N andFIG. 18O is shown in FIG. 18P. The mass basis cumulative particle sizedistribution 1806 corresponds to the left y-axis in the graph (Q³(x)[%]). The histogram of the mass particle size distribution 1808corresponds to the right axis in the graph (dQ³(x) [%]). The medianparticle size is approximately 33 μm. The 10th percentile particle sizeis approximately 9 μm, and the 90th percentile particle size isapproximately 103 μm. The mass density of the particles is approximately10 g/L.

Example 4

The particle size distribution of the carbon particles captured from amultiple-stage reactor is shown in FIG. 18Q. The mass basis cumulativeparticle size distribution 1814 corresponds to the left y-axis in thegraph (Q³(x) [%]). The histogram of the mass particle size distribution1816 corresponds to the right axis in the graph (dQ³(x) [%]). The medianparticle size captured is approximately 11 μm. The 10th percentileparticle size is approximately 3.5 μm, and the 90th percentile particlesize is approximately 21 μm. The graph in FIG. 18Q also shows the numberbasis cumulative particle size distribution 1818 corresponding to theleft y-axis in the graph (Q° (x) [%]). The median particle size bynumber basis is from approximately 0.1 μm to approximately 0.2 μm.

Returning to the discussion of FIG. 18P, the graph also shows a secondset of example results. Specifically, in this example, the particleswere size-reduced by mechanical grinding, and then the size-reducedparticles were processed using a cyclone separator. The mass basiscumulative particle size distribution 410 of the size-reduced carbonparticles captured in this example corresponds to the left y-axis in thegraph (Q³(x) [%]). The histogram of the mass basis particle sizedistribution 412 corresponds to the right axis in the graph (dQ³(x)[%]). The median particle size of the size-reduced carbon particlescaptured in this example is approximately 6 μm. The 10th percentileparticle size is from 1 μm to 2 μm, and the 90th percentile particlesize is from 10 μm to 20 μm.

Further details pertaining to making and using cyclone separators can befound in U.S. patent application Ser. No. 15/725,928, filed Oct. 5,2017, titled “MICROWAVE REACTOR SYSTEM WITH GAS-SOLIDS SEPARATION”,which is hereby incorporated by reference in its entirety.

In some cases, carbon particles and aggregates containing graphite,graphene and amorphous carbon can be generated using a microwave plasmareactor system using a precursor material that contains methane, orcontains isopropyl alcohol (IPA), or contains ethanol, or contains acondensed hydrocarbon (such as, hexane). In some other examples, thecarbon-containing precursors are optionally mixed with a supply gas(such as, argon). The particles produced in this example containedgraphite, graphene, amorphous carbon, and no seed particles. Theparticles in this example had a ratio of carbon to other elements (otherthan hydrogen) of approximately 99.5% or greater.

In one particular example, a hydrocarbon was the input material for themicrowave plasma reactor, and the separated outputs of the reactorcomprised hydrogen gas and carbon particles containing graphite,graphene, and amorphous carbon. The carbon particles were separated fromthe hydrogen gas in a multi-stage gas-solid separation system. Thesolids loading of the separated outputs from the reactor was from 0.001g/L to 2.5 g/L.

Example 5

FIG. 18R, FIG. 18S, and FIG. 18T are TEM images of as-synthesized carbonnanoparticles. The images show examples of graphite, graphene, andamorphous carbon allotropes. The layers of graphene and other carbonmaterials can be clearly seen in the images.

The particle size distribution of the carbon particles captured is shownin FIG. 18U. The mass basis cumulative particle size distribution 1820corresponds to the left y-axis in the graph (Q³(x) [%]). The histogramof the mass particle size distribution 1822 corresponds to the rightaxis in the graph (dQ³(x) [%]). The median particle size captured in thecyclone separator in this example was approximately 14 μm. The 10thpercentile particle size was approximately 5 μm, and the 90th percentileparticle size was approximately 28 μm. The graph in FIG. 18U also showsthe number basis cumulative particle size distribution 424 correspondingto the left y-axis in the graph (Q° (x) [%]). The median particle sizeby number basis in this example was from approximately 0.1 μm toapproximately 0.2 μm.

FIG. 18V, FIG. 18W, and FIG. 18X, and 18X are images that showthree-dimensional carbon-containing structures that are grown onto otherthree-dimensional structures. FIG. 18V is a 100× magnification ofthree-dimensional carbon structures grown onto carbon fibers, whereasFIG. 18W is a 200× magnification of three-dimensional carbon structuresgrown onto carbon fibers. FIG. 18X is a 1601× magnification ofthree-dimensional carbon structures grown onto carbon fibers. Thethree-dimensional carbon growth over the fiber surface is shown. FIG.18Y is a 10000× magnification of three-dimensional carbon structuresgrown onto carbon fibers. The image depicts growth onto the basal planeas well as onto edge planes.

More specifically, FIGS. 18V— 18Y show example SEM images of 3D carbonmaterials grown onto fibers using plasma energy from a microwave plasmareactor as well as thermal energy from a thermal reactor. FIG. 18V showsan SEM image of intersecting fiber 1831 and fiber 1832 with 3D carbonmaterial 1830 grown on the surface of the fibers. FIG. 18W is a highermagnification image (the scale bar is 300 μm compared to 500 μm for FIG.18V) showing the 3D carbon material 1830 on the fiber 1832. FIG. 18X isa further magnified view (scale bar is 40 μm) showing the 3D carbonmaterial 1830 on fiber surface 1835, where the 3D nature of the 3Dcarbon material 1830 can be clearly seen. FIG. 18Y shows a close-up view(scale bar is 500 nm) of the carbon alone, showing interconnectionbetween basal planes of the fiber 1832 and edge planes 1834 of numeroussub-particles of the 3D carbon material grown on the fiber. FIGS. 18V—18Y demonstrate the ability to grow 3D carbon on a 3D fiber structure,such as 3D carbon growth grown on a 3D carbon fiber.

3D carbon growth on fibers can be achieved by introducing a plurality offibers into the microwave plasma reactor and using plasma in themicrowave reactor to etch the fibers. The etching creates nucleationsites such that when carbon particles and sub-particles are created byhydrocarbon disassociation in the reactor, growth of 3D carbonstructures is initiated at these nucleation sites. The direct growth ofthe 3D carbon structures on the fibers, which themselves arethree-dimensional in nature, provides a highly integrated, 3D structurewith pores into which resin can permeate. This 3D reinforcement matrix(including the 3D carbon structures integrated with high aspect ratioreinforcing fibers) for a resin composite results in enhanced materialproperties, such as tensile strength and shear, compared to compositeswith conventional fibers that have smooth surfaces, and which smoothsurfaces typically delaminate from the resin matrix.

Carbon materials, such as any one or more of the 3D carbon materialsdescribed herein, can have one or more exposed surfaces prepared forfunctionalization, such as that to promote adhesion and/or add elementssuch as oxygen, nitrogen, carbon, silicon, or hardening agents.Functionalization refers to the addition of functional groups to acompound by chemical synthesis. In materials science, functionalizationcan be employed to achieve desired surface properties; for instance,functional groups can also be used to covalently link functionalmolecules to the surfaces of chemical devices. The carbon materials canbe functionalized in-situ—that is, on site within the same reactor inwhich the carbon materials are produced. The carbon materials can befunctionalized in post-processing. For example, the surfaces offullerenes or graphene can be functionalized with oxygen- ornitrogen-containing species which form bonds with polymers of the resinmatrix, thus improving adhesion and providing strong binding to enhancethe strength of composites.

Functionalizing surface treatments can be performed on any one or moreof the disclosed carbon-based materials (such as, CNTs, CNO, graphene,3D carbon materials such as 3D graphene) utilizing plasma reactors (suchas, microwave plasma reactors) described herein. Such treatments caninclude in-situ surface treatment during creation of carbon materialsthat can be combined with a binder or polymer in a composite material,or surface treatment after creation of the carbon materials while thecarbon materials are still within the reactor.

Some of the foregoing embodiments include resonators that include aplurality of three-dimensional (3D) aggregates formed ofcarbon-containing material that is embedded within a ply or plies oftire. However, some embodiments include resonators that are printed orotherwise disposed on an inner surface of a tire (e.g., on an innerliner of the tire).

In the foregoing specification, the disclosure has been described withreference to specific implementations thereof. It will however beevident that various modifications and changes may be made theretowithout departing from the broader spirit and scope of the disclosure.For example, the above-described process flows are described withreference to an ordering of process actions. However, the ordering ofmany of the described process actions may be changed without affectingthe scope or operation of the disclosure. The specification and drawingsare to be regarded in an illustrative sense rather than in a restrictivesense.

What is claimed is:
 1. A tire including a temperature sensor associatedwith one or more tire plies within the tire, the temperature sensorcomprising: one or more split-ring resonators (SRRs), each SRR having arespective resonance frequency that changes by an amount in response toone or more of a change in an elastomeric property of a respective tireply or a change in temperature of the respective tire ply; and anelectrically-conductive layer dielectrically separated from the one ormore SRRs.
 2. The tire of claim 1, wherein the temperature sensor isconfigured to determine the temperature of the one or more tire plies.3. The tire of claim 1, wherein the one or more SRRs arethree-dimensionally printed onto a surface of at least one of the tireplies.
 4. The tire of claim 1, wherein the amount of change in theresonance frequency of a respective SRR is indicative of an extent ofwear of at least the respective tire ply.
 5. The tire of claim 1,wherein the amount of change in the resonance frequency of a respectiveSRR is indicative of a change in the temperature of at least therespective tire ply.
 6. The tire of claim 1, wherein at least one of theone or more SRRs has an oval shape, an elliptical shape, a rectangularshape, a square shape, or a circle shape.
 7. The tire of claim 1,wherein at least one of the one or more SRRs comprises a cylindricalSRR.
 8. The tire of claim 1, wherein each of the one or more SRRs has anegative effective permeability.
 9. The tire of claim 1, wherein the oneor more SRRs are arranged as concentric rings relative to one another.10. The tire of claim 1, wherein a first SRR of the one or more SRRsresonates at a first frequency in response to an electromagnetic ping,and a second SRR of the one or more SRRs resonates at a second frequencyin response to the electromagnetic ping.
 11. The tire of claim 10,wherein the first frequency is different than the second frequency. 12.The tire of claim 10, wherein the first frequency is indicative of afirst serial number, and the second frequency is indicative of a secondserial number.
 13. The tire of claim 12, wherein the first serial numberidentifies a first tire ply of the one or more tire plies, and thesecond number identifies a second tire ply of the one or more tireplies.
 14. The tire of claim 12, wherein the first and second serialnumbers identify the tire.
 15. The tire of claim 10, wherein the firstSRR includes a first concentration of carbon particles, the second SRRincludes a second concentration of carbon particles, and the firstconcentration of carbon particles is different than the secondconcentration of carbon particles.
 16. The tire of claim 15, wherein thefirst concentration of carbon particles causes the first SRR to resonateat a first frequency in response to an electromagnetic ping, the secondconcentration of carbon particles causes the second SRR to resonate at asecond frequency in response to the electromagnetic ping, and the firstfrequency is different than the second frequency.
 17. The tire of claim15, wherein the first SRR includes a first porous structure formed byaggregates of least some of the first concentration of carbon particles,and the second SRR includes a second porous structure formed byaggregates of least some of the second concentration of carbonparticles.
 18. The tire of claim 15, wherein the first concentration ofcarbon particles is chemically bonded with a first tire ply, and thesecond concentration of carbon particles is chemically bonded with asecond tire ply.
 19. The tire of claim 10, wherein the first SRR ispositioned outside the second SRR.
 20. The tire of claim 10, wherein thefirst SRR and the second SRR are disposed within an inner liner of thetire.